Merge branch 'main' into gatekeeper/fix-2369-1

.agents/skills/README.md

@@ -5,7 +5,3 @@ This directory contains repo-scoped code agent skills for the LanceDB project.
 Each skill is a folder that contains a required `SKILL.md` and optional bundled resources.
 
 Codex discovers skills from `.agents/skills` in the current working directory and parent directories.
-
-The `lancedb` skill lives in the `plugins/lancedb` plugin (see `plugins/lancedb/skills/lancedb`)
-so it can be installed via the plugin marketplaces (`.claude-plugin/marketplace.json` and
-`.agents/plugins/marketplace.json`); the `lancedb` entry here is a symlink into that plugin.

.agents/skills/lancedb

@@ -1 +0,0 @@
-../../plugins/lancedb/skills/lancedb

.bumpversion.toml

@@ -1,5 +1,5 @@
 [tool.bumpversion]
-current_version = "0.37.1-beta.0"
+current_version = "0.38.0-beta.3"
 parse = """(?x)
     (?P<major>0|[1-9]\\d*)\\.
     (?P<minor>0|[1-9]\\d*)\\.

.cargo/config.toml

@@ -9,6 +9,18 @@ debug = true
 codegen-units = 16
 lto = "thin"
 
+[profile.release-no-lto]
+inherits = "release"
+debug = true
+lto = false
+# Prioritize compile time when LTO is not relevant to the measurement.
+codegen-units = 16
+
+[profile.bench]
+inherits = "release"
+lto = "thin"
+codegen-units = 16
+
 [target.'cfg(all())']
 rustflags = [
     "-Wclippy::all",

.github/dependabot.yml

@@ -17,6 +17,18 @@ updates:
     # newer minimum versions.
     versioning-strategy: lockfile-only
     groups:
+      # The arrow-rs and datafusion crates are released in lockstep and have to
+      # move together, so keep them in one PR instead of one per sub-crate.
+      # Listed first: a dependency joins the first group it matches.
+      arrow-datafusion:
+        patterns:
+          - arrow
+          - arrow-*
+          - parquet
+          - parquet-*
+          - datafusion
+          - datafusion-*
+          - object_store
       rust-minor-patch:
         update-types:
           - minor

.github/workflows/ci-scripts.yml

@@ -0,0 +1,30 @@
+name: CI scripts
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - ci/set_lance_version.py
+      - ci/tests/**
+      - .github/workflows/ci-scripts.yml
+  pull_request:
+    paths:
+      - ci/set_lance_version.py
+      - ci/tests/**
+      - .github/workflows/ci-scripts.yml
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Test CI scripts
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/setup-python@v6
+        with:
+          python-version: "3.13"
+      - name: Run tests
+        run: python -m unittest discover -s ci/tests -v

.github/workflows/codex-update-lance-dependency.yml

@@ -4,14 +4,14 @@ on:
   workflow_call:
     inputs:
       tag:
-        description: "Tag name from Lance. If omitted, the skill will use the latest Lance release that needs an update."
+        description: "Tag name from Lance (e.g. `v7.2.0-beta.1`). If omitted, the newest release is resolved automatically — stable releases are preferred over pre-releases — and the run is skipped if it is not newer than the version currently pinned in Cargo.toml."
         required: false
         default: ""
         type: string
   workflow_dispatch:
     inputs:
       tag:
-        description: "Tag name from Lance. Leave empty to use the latest Lance release that needs an update."
+        description: "Tag name from Lance (e.g. `v7.2.0-beta.1`). Leave empty to resolve the newest release automatically — stable releases are preferred over pre-releases — and skip the run if it is not newer than the version currently pinned in Cargo.toml."
         required: false
         default: ""
         type: string

.github/workflows/docs-link-check.yml

@@ -0,0 +1,243 @@
+name: Check doc links
+
+# Checking external links is inherently noisy: third-party sites rate-limit
+# automated clients, reject non-browser user agents, and go down temporarily.
+# Blocking pull requests on that trades a lot of false failures for very little
+# signal, so this runs on a schedule and reports findings in a single tracking
+# issue instead of failing anyone's build.
+on:
+  schedule:
+    - cron: "0 7 * * *"
+  workflow_dispatch:
+
+# The report lives in one repository-global issue, so runs must not overlap: a
+# lookup racing a create produces duplicate issues, and a healthy run closing
+# the issue while a failing run only rewrites its body would leave a broken
+# report closed. The group is deliberately ref-independent so that a manual
+# dispatch serializes against the scheduled run.
+concurrency:
+  group: docs-link-check
+  cancel-in-progress: false
+
+permissions: {}
+
+env:
+  REPORT_TITLE: "Docs link checker report"
+
+jobs:
+  scan:
+    name: Scan links
+    runs-on: ubuntu-24.04
+    # lychee-action is pinned by SHA, but its wrapper downloads the lychee
+    # release tarball at run time without verifying a digest, and hands the
+    # resulting binary a GitHub token. Release assets remain replaceable, so
+    # that binary is confined to a job whose token can only read public
+    # content; everything that writes runs in the report job below.
+    permissions:
+      contents: read
+    outputs:
+      checker_outcome: ${{ steps.lychee.outcome }}
+      exit_code: ${{ steps.lychee.outputs.exit_code }}
+      status: ${{ steps.validate.outputs.status }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          # workflow_dispatch can run from any ref, but the report is
+          # repository-global. Always measure the default branch so a manual
+          # run from a topic branch cannot close a report that main warrants,
+          # or overwrite it with branch-only findings.
+          ref: ${{ github.event.repository.default_branch }}
+          persist-credentials: false
+
+      - name: Check links
+        id: lychee
+        continue-on-error: true
+        uses: lycheeverse/lychee-action@e7477775783ea5526144ba13e8db5eec57747ce8 # v2.9.0
+        with:
+          # Restricted to http(s) on purpose. Much of docs/src is generated
+          # API reference (the js/ tree comes from `npm run docs` in nodejs)
+          # and the hand-written pages use mkdocstrings cross-references and
+          # nav-relative paths that only resolve in the site mkdocs builds,
+          # not in this checkout, so relative links would be reported as
+          # broken on every run.
+          args: >-
+            --scheme https
+            --scheme http
+            --no-progress
+            --max-retries 3
+            --timeout 20
+            'docs/src/**/*.md'
+          format: json
+          output: ./lychee/out.json
+          jobSummary: false
+          # The report issue, not a red workflow run, is the signal for link
+          # findings and checker failures alike.
+          fail: false
+
+      - name: Validate report
+        id: validate
+        # lychee does not reserve exit code 2 for broken links: its CLI
+        # parser also exits 2 on an invalid option, before any link was
+        # checked or any report written. Only a parseable report whose
+        # counts agree with a completed exit code (0 or 2) counts as a link
+        # verdict. Everything else becomes a checker-error report instead of
+        # failing the workflow. Exit 2 covers timeouts as well as errors, and a
+        # timed-out host is exactly the transient unavailability this report
+        # exists to surface, so both count as findings. Requiring total > 0
+        # also catches a glob that silently stopped matching any file.
+        if: always()
+        env:
+          CHECKER_OUTCOME: ${{ steps.lychee.outcome }}
+          EXIT_CODE: ${{ steps.lychee.outputs.exit_code }}
+        run: |
+          status=checker-error
+          if [[ "$CHECKER_OUTCOME" == success ]] &&
+             [[ "$EXIT_CODE" == 0 || "$EXIT_CODE" == 2 ]] &&
+             jq -e --argjson code "$EXIT_CODE" '
+               (.total > 0) and
+               (if $code == 0
+                then .errors == 0 and .timeouts == 0
+                  and (.error_map | length == 0) and (.timeout_map | length == 0)
+                else (.errors + .timeouts) > 0
+                  and ((.error_map | length) + (.timeout_map | length)) > 0
+                end)
+             ' ./lychee/out.json
+          then
+            if [[ "$EXIT_CODE" == 0 ]]; then
+              status=healthy
+            else
+              status=findings
+            fi
+          fi
+          echo "status=$status" >> "$GITHUB_OUTPUT"
+          echo "Validated link check as $status"
+
+      - name: Upload report
+        if: steps.validate.outputs.status == 'findings'
+        uses: actions/upload-artifact@v7
+        with:
+          name: link-report
+          path: ./lychee/out.json
+          retention-days: 7
+
+  report:
+    name: Update report issue
+    needs: scan
+    runs-on: ubuntu-24.04
+    # Deliberately no checkout: this job needs the report artifact and the
+    # issues API, not the repository contents.
+    permissions:
+      issues: write
+    env:
+      CHECKER_OUTCOME: ${{ needs.scan.outputs.checker_outcome }}
+      EXIT_CODE: ${{ needs.scan.outputs.exit_code }}
+      STATUS: ${{ needs.scan.outputs.status }}
+      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - name: Find existing report issue
+        id: report
+        # Matched on title alone, and through search rather than a listing:
+        # the issue action applies labels in a separate call after creating the
+        # issue, so a label filter misses a half-created report, and this
+        # repository has far more open issues than one listing page holds.
+        # Closed issues are included because a healthy run closes the report:
+        # an open-only lookup would forget that identity and the next failing
+        # run would open a duplicate. The oldest match stays the canonical
+        # report and is reopened below when a problem recurs.
+        run: |
+          match=$(gh issue list --repo "$GITHUB_REPOSITORY" --state all \
+            --search "in:title \"$REPORT_TITLE\" author:app/github-actions" \
+            --limit 50 --json number,title,state \
+            --jq "[.[] | select(.title == \"$REPORT_TITLE\")] | sort_by(.number) | first // empty")
+          echo "number=$(jq -r '.number // empty' <<<"$match")" >> "$GITHUB_OUTPUT"
+          echo "state=$(jq -r '.state // empty' <<<"$match")" >> "$GITHUB_OUTPUT"
+
+      - name: Download report
+        if: env.STATUS == 'findings'
+        uses: actions/download-artifact@v8
+        with:
+          name: link-report
+          path: ./lychee
+
+      - name: Compose report
+        if: env.STATUS == 'findings'
+        run: |
+          run_url="$GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID"
+          {
+            echo "Broken documentation links found by [\`$GITHUB_WORKFLOW\`]($run_url)."
+            echo
+            echo "This issue is rewritten by every scheduled run and closed automatically once all links resolve."
+            echo
+            echo "Entries can be false positives: some sites rate-limit or block automated clients while working fine in a browser. Confirm before editing the docs, and add persistent offenders to \`--exclude\` in \`.github/workflows/docs-link-check.yml\`."
+            echo
+            # Timeouts are reported alongside errors: entries land in
+            # timeout_map with a status text instead of an HTTP code.
+            jq -r '
+              "\(.errors) of \(.total) links failed, \(.timeouts) timed out.",
+              "",
+              ([(.error_map | to_entries[]), (.timeout_map | to_entries[])]
+               | group_by(.key)[] |
+                "### Errors in \(.[0].key)",
+                "",
+                (map(.value[])[] | "* [\(.status.code // .status.text // "ERR")] <\(.url)> — \(.status.details // .status.text // "unknown error")"),
+                "")
+            ' ./lychee/out.json
+          } > ./lychee/issue.md
+
+      - name: Compose checker error report
+        if: env.STATUS == 'checker-error'
+        run: |
+          mkdir -p ./lychee
+          run_url="$GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID"
+          {
+            echo "The documentation link check did not complete in [the latest run]($run_url)."
+            echo
+            echo "This issue is rewritten by every scheduled run and closed automatically once a trustworthy run finds that all links resolve."
+            echo
+            echo "The checker did not produce a trustworthy link verdict. Treat the previous result, if any, as stale until a later run completes."
+            echo
+            echo "* Action outcome: \`$CHECKER_OUTCOME\`"
+            echo "* Exit code: \`${EXIT_CODE:-not reported}\`"
+            echo "* Verdict validation: \`failed\`"
+          } > ./lychee/issue.md
+
+      - name: Reopen report issue
+        # A healthy run closes the report, and the issue action below only
+        # rewrites the body of whatever number it is given. Without an
+        # explicit reopen, a later finding or checker error would rewrite a
+        # closed issue. A CLOSED state implies the lookup found a canonical
+        # issue, so no separate emptiness check.
+        if: >-
+          env.STATUS != 'healthy' &&
+          steps.report.outputs.state == 'CLOSED'
+        env:
+          ISSUE_NUMBER: ${{ steps.report.outputs.number }}
+        run: |
+          run_url="$GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID"
+          gh issue reopen "$ISSUE_NUMBER" --repo "$GITHUB_REPOSITORY" \
+            --comment "The documentation link checker reported a problem again in [the latest run]($run_url)."
+
+      - name: Report link-check problem
+        if: env.STATUS != 'healthy'
+        uses: peter-evans/create-issue-from-file@fca9117c27cdc29c6c4db3b86c48e4115a786710 # v6.0.0
+        with:
+          # Empty on the first failing run, which creates the issue; afterwards
+          # the same issue is updated in place.
+          issue-number: ${{ steps.report.outputs.number }}
+          title: ${{ env.REPORT_TITLE }}
+          content-filepath: ./lychee/issue.md
+          labels: documentation
+
+      - name: Close report issue once links are healthy
+        # An OPEN state implies the lookup found a canonical issue; a report
+        # that is already closed needs nothing.
+        if: >-
+          env.STATUS == 'healthy' &&
+          steps.report.outputs.state == 'OPEN'
+        env:
+          ISSUE_NUMBER: ${{ steps.report.outputs.number }}
+        run: |
+          run_url="$GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID"
+          gh issue close "$ISSUE_NUMBER" --repo "$GITHUB_REPOSITORY" \
+            --comment "All documentation links resolved in [the latest run]($run_url)."

.github/workflows/pypi-publish.yml

@@ -69,6 +69,16 @@ jobs:
         uses: actions/setup-python@v6
         with:
           python-version: "3.10"
+      - name: Add swap for Arm fat LTO
+        if: matrix.config.platform == 'aarch64'
+        shell: bash
+        run: |
+          swap_file="$RUNNER_TEMP/lancedb-swap"
+          sudo fallocate --length 16G "$swap_file"
+          sudo chmod 600 "$swap_file"
+          sudo mkswap "$swap_file"
+          sudo swapon "$swap_file"
+          free -h
       - uses: ./.github/workflows/build_linux_wheel
         with:
           python-minor-version: 10
@@ -119,6 +129,12 @@ jobs:
       # link.exe is single-threaded and the long pole on Windows builds. Use
       # rustc's bundled lld-link instead.
       CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER: rust-lld
+      # Fat LTO of the cdylib is single-threaded and the peak-memory step of the
+      # build. ThinLTO parallelizes it across the runner's cores, at some cost
+      # to runtime performance on our least performance-sensitive platform.
+      # Matches what the nodejs Windows builds already do in npm-publish.yml.
+      CARGO_PROFILE_RELEASE_LTO: thin
+      CARGO_PROFILE_RELEASE_CODEGEN_UNITS: 16
     steps:
       - uses: actions/checkout@v6
         with:

.github/workflows/python.yml

@@ -229,7 +229,8 @@ jobs:
       # Make sure wheels are not included in the Rust cache
       - name: Delete wheels
         run: rm -rf target/wheels
-  pydantic1x:
+  min-deps:
+    name: "Minimum dependencies"
     timeout-minutes: 60
     runs-on: "ubuntu-24.04"
     defaults:
@@ -259,8 +260,7 @@ jobs:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: Install lancedb
         run: |
-          pip install "pydantic<2"
-          pip install pyarrow==16
+          pip install "pydantic==2.7.4" "pyarrow==16"
           pip install --extra-index-url https://pypi.fury.io/lance-format/ --extra-index-url https://pypi.fury.io/lancedb/ -e .[tests]
       - name: Run tests
         run: pytest -m "not slow and not s3_test" -x -v --durations=30 python/tests

.github/workflows/rust.yml

@@ -121,7 +121,6 @@ jobs:
       # Need up-to-date compilers for kernels
       CC: clang-18
       CXX: clang++-18
-      GH_TOKEN: ${{ secrets.SOPHON_READ_TOKEN }}
     steps:
       - uses: actions/checkout@v6
         with:
@@ -165,11 +164,40 @@ jobs:
       - name: Run feature tests
         run: CARGO_ARGS="--profile ci" make -C ./lancedb feature-tests
       - name: Run examples
-        run: cargo run  --profile ci --example simple --locked
+        run: cargo run --profile ci --all-features --example simple --locked
+
+  remote:
+    timeout-minutes: 30
+    # Running this requires access to secrets, so skip if this is a PR from a
+    # fork. Keep it separate from the all-features build so Cargo does not
+    # retain both dependency graphs in one target directory.
+    if: github.event_name != 'pull_request' || !github.event.pull_request.head.repo.fork
+    runs-on: ubuntu-2404-4x-x64
+    defaults:
+      run:
+        shell: bash
+        working-directory: rust
+    env:
+      CC: clang-18
+      CXX: clang++-18
+      GH_TOKEN: ${{ secrets.SOPHON_READ_TOKEN }}
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+          lfs: true
+      - uses: Swatinem/rust-cache@v2
+        with:
+          # Remote tests use a different feature graph from the main Linux
+          # job. Cache downloads, but build into a fresh target directory.
+          cache-targets: false
+          save-if: ${{ github.ref == 'refs/heads/main' }}
+      - name: Install dependencies
+        run: |
+          sudo apt update
+          sudo apt install -y protobuf-compiler libssl-dev
+      - uses: rui314/setup-mold@v1
       - name: Run remote tests
-        # Running this requires access to secrets, so skip if this is
-        # a PR from a fork.
-        if: github.event_name != 'pull_request' || !github.event.pull_request.head.repo.fork
         run: CARGO_ARGS="--profile ci" make -C ./lancedb remote-tests
 
   macos:
@@ -296,16 +324,18 @@ jobs:
           cargo update -p aws-types --precise 1.3.9
           cargo update -p aws-sigv4 --precise 1.3.5
           cargo update -p aws-credential-types --precise 1.2.8
-          cargo update -p aws-smithy-checksums --precise 0.63.9
+          # aws-smithy-checksums must stay at or above 0.63.13: OpenDAL's S3
+          # service needs crc-fast ~1.9, and older releases pin it to ~1.3.
+          cargo update -p aws-smithy-checksums --precise 0.63.13
           cargo update -p aws-smithy-runtime --precise 1.9.3
-          cargo update -p aws-smithy-http --precise 0.62.4
-          cargo update -p aws-smithy-eventstream --precise 0.60.12
+          cargo update -p aws-smithy-http --precise 0.62.6
+          cargo update -p aws-smithy-eventstream --precise 0.60.14
           cargo update -p aws-smithy-http-client --precise 1.1.3
           cargo update -p aws-smithy-observability --precise 0.1.4
           cargo update -p aws-smithy-query --precise 0.60.8
-          cargo update -p aws-smithy-runtime-api --precise 1.9.1
-          cargo update -p aws-smithy-async --precise 1.2.6
-          cargo update -p aws-smithy-types --precise 1.3.5
+          cargo update -p aws-smithy-runtime-api --precise 1.9.3
+          cargo update -p aws-smithy-async --precise 1.2.7
+          cargo update -p aws-smithy-types --precise 1.3.6
           cargo update -p aws-smithy-xml --precise 0.60.11
           cargo update -p home --precise 0.5.9
       - name: cargo +${{ matrix.msrv }} check

AGENTS.md

@@ -18,6 +18,9 @@ Common commands:
 * Run specific test: `cargo test --quiet --features remote -p <package_name> --test <test_name>`
 * Lint: `cargo clippy --quiet --features remote --tests --examples`
 * Format Rust: `cargo fmt --all`
+* Use repository-defined Cargo profiles instead of ad hoc LTO overrides.
+* Use `release-with-debug` for benchmarks and profiling so optimized builds keep debug symbols without a rebuild.
+* Use `release-no-lto` only for local debugging, IO-bound benchmarks, or compile-time-sensitive performance investigation where LTO would not affect the measured bottleneck.
 * Format Python: `ruff format .`
 * Lint Python: `ruff check .`
 * Bootstrap Python dev env: `cd python && uv run --extra tests --extra dev maturin develop --extras tests,dev`

Cargo.toml

@@ -13,20 +13,21 @@ categories = ["database-implementations"]
 rust-version = "1.91.0"
 
 [workspace.dependencies]
-lance = { "version" = "=10.1.0-beta.1", default-features = false, "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-core = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-datagen = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-file = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-io = { "version" = "=10.1.0-beta.1", default-features = false, "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-index = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-linalg = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-namespace = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-namespace-impls = { "version" = "=10.1.0-beta.1", default-features = false, "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-table = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-testing = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-datafusion = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-encoding = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
-lance-arrow = { "version" = "=10.1.0-beta.1", "tag" = "v10.1.0-beta.1", "git" = "https://github.com/lance-format/lance.git" }
+lance = { "version" = "=11.0.0-beta.18", default-features = false, "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-core = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-datagen = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-file = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-io = { "version" = "=11.0.0-beta.18", default-features = false, "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-index = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-linalg = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-namespace = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-namespace-impls = { "version" = "=11.0.0-beta.18", default-features = false, "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-table = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-testing = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-datafusion = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-encoding = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lance-arrow = { "version" = "=11.0.0-beta.18", "tag" = "v11.0.0-beta.18", "git" = "https://github.com/lance-format/lance.git" }
+lancedb = { path = "rust/lancedb", default-features = false }
 ahash = "0.8"
 # Note that this one does not include pyarrow
 arrow = { version = "58.0.0", optional = false }
@@ -39,6 +40,7 @@ arrow-schema = "58.0.0"
 arrow-select = "58.0.0"
 arrow-cast = "58.0.0"
 async-trait = "0"
+bytes = "1"
 datafusion = { version = "54.0.0", default-features = false }
 datafusion-catalog = "54.0.0"
 datafusion-common = { version = "54.0.0", default-features = false }
@@ -52,7 +54,7 @@ env_logger = "0.11"
 half = { "version" = "2.7.1", default-features = false, features = [
     "num-traits",
 ] }
-futures = "0"
+futures = "0.3"
 log = "0.4"
 metrics = "0.24"
 metrics-util = "0.19"
@@ -65,7 +67,12 @@ url = "2"
 num-traits = "0.2"
 regex = "1.10"
 semver = "1.0.25"
-chrono = "0.4"
+serde = "1"
+serde_json = "1"
+tempfile = "3.5.0"
+tokio = { version = "1.23", features = ["rt-multi-thread", "sync"] }
+uuid = { version = "1.7.0", features = ["v4"] }
+chrono = { version = "0.4", default-features = false, features = ["clock"] }
 
 [profile.ci]
 debug = "line-tables-only"

ci/check_breaking_changes.py

@@ -2,6 +2,7 @@
 Check whether there are any breaking changes in the PRs between the base and head commits.
 If there are, assert that we have incremented the minor version.
 """
+
 import argparse
 import os
 from packaging.version import parse
@@ -27,7 +28,7 @@ if __name__ == "__main__":
     else:
         print("No breaking changes found.")
         exit(0)
-    
+
     last_stable_version = parse(args.last_stable_version)
     current_version = parse(args.current_version)
     if current_version.minor <= last_stable_version.minor:

ci/check_lance_release.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 """Determine whether a newer Lance tag exists and expose results for CI."""
+
 from __future__ import annotations
 
 import argparse
@@ -36,8 +37,16 @@ class SemVer:
     prerelease: Tuple[Union[int, str], ...]
 
     def __lt__(self, other: "SemVer") -> bool:  # pragma: no cover - simple comparison
-        if (self.major, self.minor, self.patch) != (other.major, other.minor, other.patch):
-            return (self.major, self.minor, self.patch) < (other.major, other.minor, other.patch)
+        if (self.major, self.minor, self.patch) != (
+            other.major,
+            other.minor,
+            other.patch,
+        ):
+            return (self.major, self.minor, self.patch) < (
+                other.major,
+                other.minor,
+                other.patch,
+            )
         if self.prerelease == other.prerelease:
             return False
         if not self.prerelease:
@@ -142,7 +151,9 @@ def read_current_version(repo_root: Path) -> str:
         deps = data["workspace"]["dependencies"]
         entry = deps["lance"]
     except KeyError as exc:  # pragma: no cover - configuration guard
-        raise RuntimeError("Failed to locate workspace.dependencies.lance in Cargo.toml") from exc
+        raise RuntimeError(
+            "Failed to locate workspace.dependencies.lance in Cargo.toml"
+        ) from exc
 
     if isinstance(entry, str):
         raw_version = entry

ci/mock_openai.py

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright The LanceDB Authors
 """A zero-dependency mock OpenAI embeddings API endpoint for testing purposes."""
+
 import argparse
 import json
 import http.server
@@ -22,11 +23,13 @@ class MockOpenAIRequestHandler(http.server.BaseHTTPRequestHandler):
 
         data = []
         for i in range(num_inputs):
-            data.append({
-                "object": "embedding",
-                "embedding": [0.1] * 1536,
-                "index": i,
-            })
+            data.append(
+                {
+                    "object": "embedding",
+                    "embedding": [0.1] * 1536,
+                    "index": i,
+                }
+            )
 
         response = {
             "object": "list",
@@ -35,7 +38,7 @@ class MockOpenAIRequestHandler(http.server.BaseHTTPRequestHandler):
             "usage": {
                 "prompt_tokens": 0,
                 "total_tokens": 0,
-            }
+            },
         }
 
         self.send_response(200)

ci/semver_sort.py

@@ -7,6 +7,7 @@ from packaging.version import parse, InvalidVersion
 
 if __name__ == "__main__":
     import argparse
+
     parser = argparse.ArgumentParser()
     parser.add_argument("prefix", default="v")
     args = parser.parse_args()

ci/set_lance_version.py

@@ -22,7 +22,7 @@ def run_command(command: str) -> str:
 def get_latest_stable_version() -> str:
     version_line = run_command("cargo info lance | grep '^version:'")
     # Example output: "version: 0.35.0 (latest 0.37.0)"
-    match = re.search(r'\(latest ([0-9.]+)\)', version_line)
+    match = re.search(r"\(latest ([0-9.]+)\)", version_line)
     if match:
         return match.group(1)
     # Fallback: use the first version after 'version:'
@@ -69,7 +69,7 @@ def extract_default_features(line: str) -> bool:
     """
     import re
 
-    match = re.search(r'default-features\s*=\s*false', line)
+    match = re.search(r"default-features\s*=\s*false", line)
     return match is not None
 
 
@@ -104,7 +104,7 @@ def dict_to_toml_line(package_name: str, config: dict) -> str:
             # This shouldn't happen with our current usage
             parts.append(f'"{key}" = {json.dumps(value)}')
 
-    return f'{package_name} = {{ {", ".join(parts)} }}\n'
+    return f"{package_name} = {{ {', '.join(parts)} }}\n"
 
 
 def update_cargo_toml(line_updater):
@@ -119,7 +119,7 @@ def update_cargo_toml(line_updater):
     lance_line = ""
     is_parsing_lance_line = False
     for line in lines:
-        if line.startswith("lance"):
+        if re.match(r"^lance(?:\s|[-_])", line):
             # Check if this is a single-line or multi-line entry
             # Single-line entries either:
             # 1. End with } (complete inline table)

ci/tests/test_set_lance_version.py

@@ -0,0 +1,185 @@
+import os
+import stat
+import subprocess
+import sys
+import tempfile
+import textwrap
+import unittest
+from pathlib import Path
+
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+SCRIPT = REPO_ROOT / "ci" / "set_lance_version.py"
+LANCE_GIT_URL = "https://github.com/lance-format/lance.git"
+
+CARGO_TOML = """\
+[workspace.dependencies]
+lance = { "version" = "=1.0.0", default-features = false, "features" = ["dynamodb"] }
+lance-core = "1.0.0"
+lance_datafusion = {
+    "version" = "=1.0.0",
+    "features" = ["substrait"]
+}
+lancedb = { path = "rust/lancedb", default-features = false }
+lancedb-common = { path = "rust/lancedb-common" }
+lancewood = "1.0.0"
+my-lance = "1.0.0"
+"""
+
+UNTOUCHED_DEPENDENCIES = """\
+lancedb = { path = "rust/lancedb", default-features = false }
+lancedb-common = { path = "rust/lancedb-common" }
+lancewood = "1.0.0"
+my-lance = "1.0.0"
+"""
+
+
+class SetLanceVersionTest(unittest.TestCase):
+    def test_supported_update_modes_only_rewrite_lance_dependencies(self):
+        cases = {
+            "stable": (
+                """\
+lance = { "version" = "=9.9.9", default-features = false, "features" = ["dynamodb"] }
+lance-core = "=9.9.9"
+lance_datafusion = { "version" = "=9.9.9", "features" = ["substrait"] }
+""",
+                ["cargo info lance", "cargo metadata"],
+            ),
+            "preview": (
+                f"""\
+lance = {{ "version" = "=10.0.0-beta.3", default-features = false, "features" = ["dynamodb"], "tag" = "v10.0.0-beta.3", "git" = "{LANCE_GIT_URL}" }}
+lance-core = {{ "version" = "=10.0.0-beta.3", "tag" = "v10.0.0-beta.3", "git" = "{LANCE_GIT_URL}" }}
+lance_datafusion = {{ "version" = "=10.0.0-beta.3", "features" = ["substrait"], "tag" = "v10.0.0-beta.3", "git" = "{LANCE_GIT_URL}" }}
+""",
+                ["git ls-remote --tags", "cargo metadata"],
+            ),
+            "local": (
+                """\
+lance = { "path" = "../lance/rust/lance", default-features = false, "features" = ["dynamodb"] }
+lance-core = { "path" = "../lance/rust/lance-core" }
+lance_datafusion = { "path" = "../lance/rust/lance_datafusion", "features" = ["substrait"] }
+""",
+                ["cargo metadata"],
+            ),
+            "v8.1.2": (
+                """\
+lance = { "version" = "=8.1.2", default-features = false, "features" = ["dynamodb"] }
+lance-core = "=8.1.2"
+lance_datafusion = { "version" = "=8.1.2", "features" = ["substrait"] }
+""",
+                ["cargo metadata"],
+            ),
+            "v8.2.0-beta.4": (
+                f"""\
+lance = {{ "version" = "=8.2.0-beta.4", default-features = false, "features" = ["dynamodb"], "tag" = "v8.2.0-beta.4", "git" = "{LANCE_GIT_URL}" }}
+lance-core = {{ "version" = "=8.2.0-beta.4", "tag" = "v8.2.0-beta.4", "git" = "{LANCE_GIT_URL}" }}
+lance_datafusion = {{ "version" = "=8.2.0-beta.4", "features" = ["substrait"], "tag" = "v8.2.0-beta.4", "git" = "{LANCE_GIT_URL}" }}
+""",
+                ["cargo metadata"],
+            ),
+        }
+
+        for version, (updated_dependencies, expected_commands) in cases.items():
+            with self.subTest(version=version), tempfile.TemporaryDirectory() as tmp:
+                workdir = Path(tmp)
+                (workdir / "Cargo.toml").write_text(CARGO_TOML)
+                command_log = workdir / "commands.log"
+                fake_bin = workdir / "bin"
+                fake_bin.mkdir()
+                self._write_fake_executables(fake_bin)
+                self._write_fake_python_dependencies(workdir)
+
+                env = os.environ.copy()
+                env["PATH"] = os.pathsep.join([str(fake_bin), env["PATH"]])
+                env["FAKE_COMMAND_LOG"] = str(command_log)
+                env["PYTHONPATH"] = os.pathsep.join(
+                    filter(None, [str(workdir), env.get("PYTHONPATH")])
+                )
+                result = subprocess.run(
+                    [sys.executable, str(SCRIPT), version],
+                    cwd=workdir,
+                    env=env,
+                    capture_output=True,
+                    text=True,
+                    timeout=10,
+                )
+
+                self.assertEqual(result.returncode, 0, result.stderr)
+                self.assertEqual(
+                    (workdir / "Cargo.toml").read_text(),
+                    "[workspace.dependencies]\n"
+                    + updated_dependencies
+                    + UNTOUCHED_DEPENDENCIES,
+                )
+                commands = command_log.read_text().splitlines()
+                for command in expected_commands:
+                    self.assertTrue(
+                        any(line.startswith(command) for line in commands),
+                        f"{command!r} not found in {commands!r}",
+                    )
+
+    def _write_fake_executables(self, fake_bin: Path) -> None:
+        cargo = fake_bin / "cargo"
+        cargo.write_text(
+            textwrap.dedent(
+                """\
+                #!/bin/sh
+                printf 'cargo %s\\n' "$*" >> "$FAKE_COMMAND_LOG"
+                case "$1" in
+                  info)
+                    printf '%s\\n' 'version: 8.8.8 (latest 9.9.9)'
+                    ;;
+                  metadata)
+                    ;;
+                  *)
+                    exit 2
+                    ;;
+                esac
+                """
+            )
+        )
+        cargo.chmod(cargo.stat().st_mode | stat.S_IXUSR)
+
+        git = fake_bin / "git"
+        git.write_text(
+            textwrap.dedent(
+                """\
+                #!/bin/sh
+                printf 'git %s\\n' "$*" >> "$FAKE_COMMAND_LOG"
+                if [ "$1" != "ls-remote" ]; then
+                  exit 2
+                fi
+                printf '%s\\n' \\
+                  '111111 refs/tags/v9.9.9' \\
+                  '222222 refs/tags/v10.0.0-beta.1' \\
+                  '333333 refs/tags/v10.0.0-beta.3'
+                """
+            )
+        )
+        git.chmod(git.stat().st_mode | stat.S_IXUSR)
+
+    def _write_fake_python_dependencies(self, workdir: Path) -> None:
+        packaging = workdir / "packaging"
+        packaging.mkdir()
+        (packaging / "__init__.py").write_text("")
+        (packaging / "version.py").write_text(
+            textwrap.dedent(
+                """\
+                class Version:
+                    def __init__(self, value):
+                        release, _, prerelease = value.partition("-beta.")
+                        self._key = (
+                            tuple(int(part) for part in release.split(".")),
+                            not prerelease,
+                            int(prerelease or 0),
+                        )
+
+                    def __lt__(self, other):
+                        return self._key < other._key
+                """
+            )
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()

ci/validate_stable_lance.py

@@ -12,7 +12,7 @@ with open("Cargo.toml", "rb") as f:
             elif isinstance(dep, dict):
                 # Version doesn't have the beta tag in it, so we instead look
                 # at the git tag.
-                version = dep.get('tag', dep.get('version'))
+                version = dep.get("tag", dep.get("version"))
             else:
                 raise ValueError("Unexpected type for dependency: " + str(dep))
 

deny.toml

@@ -101,6 +101,19 @@ ignore = [
     # https://rustsec.org/advisories/RUSTSEC-2026-0195
     { id = "RUSTSEC-2026-0194", reason = "transitive via inferno/lance/opendal; XML from trusted cloud endpoints, not attacker-controlled" },
     { id = "RUSTSEC-2026-0195", reason = "transitive via inferno/lance/opendal; XML from trusted cloud endpoints, not attacker-controlled" },
+    # smartstring: unmaintained — the repository was archived by its author on
+    # 2026-05-03. Not a vulnerability. Reached only transitively through polars
+    # (polars-core/-io/-ops/-time/-utils); nothing in LanceDB depends on it directly.
+    # The advisory states no safe upgrade is available: upstream recommends
+    # compact_str/smol_str, so clearing this requires polars to migrate.
+    # https://rustsec.org/advisories/RUSTSEC-2026-0249
+    { id = "RUSTSEC-2026-0249", reason = "smartstring unmaintained via polars; no fixed upstream release" },
+
+    # h2 0.3: empty DATA frames can be queued without limit. The patched
+    # h2 0.4 line is locked to 0.4.16, but no patched 0.3 release exists.
+    # The old copy is pulled in by aws-smithy's legacy hyper 0.14 client.
+    # https://rustsec.org/advisories/RUSTSEC-2026-0258
+    { id = "RUSTSEC-2026-0258", reason = "h2 0.3 via legacy aws-smithy/hyper 0.14; no patched 0.3 release" },
 ]
 
 # ---------------------------------------------------------------------------
@@ -164,6 +177,11 @@ multiple-versions = "warn"
 # Wildcard version requirements (`foo = "*"`) are a footgun — they let any
 # future release in without review. Ban them outright.
 wildcards = "deny"
+# Lint every dependency declared by a workspace member against the shared
+# `[workspace.dependencies]` table: any crate used by more than one member must
+# go through `workspace = true`, and entries nothing uses are an error. This
+# keeps versions from drifting between the core crate and the bindings.
+workspace-dependencies = { duplicates = "deny", unused = "deny" }
 # Internal workspace crates reference each other via `path = "..."`, which
 # cargo-deny sees as a wildcard version. That's fine for private workspace
 # members (not published to crates.io), so allow it specifically for paths.

docs/requirements.txt

@@ -5,5 +5,5 @@ mkdocs-autorefs>=0.5,<=1.0
 mkdocstrings[python]>=0.24,<1.0
 griffe>=0.40,<1.0
 mkdocs-render-swagger-plugin>=0.1.0
-pydantic>=2.0,<3.0
-mkdocs-redirects>=1.2.0
+pydantic>=2.7.4,<3
+mkdocs-redirects>=1.2.0

docs/src/java/java.md

@@ -14,7 +14,7 @@ Add the following dependency to your `pom.xml`:
 <dependency>
     <groupId>com.lancedb</groupId>
     <artifactId>lancedb-core</artifactId>
-    <version>0.37.1-beta.0</version>
+    <version>0.38.0-beta.3</version>
 </dependency>
 ```
 
@@ -55,6 +55,38 @@ LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
 | `region(String)` | AWS region (default: "us-east-1") | No |
 | `config(String, String)` | Additional configuration parameters | No |
 
+### Opening a Table with Vended Credentials
+
+When the catalog vends temporary object store credentials, open the table through the
+namespace client. The Lance dataset builder fetches the table location and storage options
+from the catalog and refreshes the credentials when they expire.
+
+```java
+import com.lancedb.LanceDbNamespaceClientBuilder;
+import org.lance.Dataset;
+import org.lance.namespace.LanceNamespace;
+
+import java.util.Arrays;
+
+LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
+    .apiKey(System.getenv("LANCEDB_API_KEY"))
+    .database(System.getenv("LANCEDB_DATABASE"))
+    // Set the endpoint for a LanceDB Enterprise deployment.
+    // .endpoint("https://your-enterprise-endpoint")
+    .build();
+
+try (Dataset dataset = Dataset.open()
+        .namespaceClient(namespaceClient)
+        .tableId(Arrays.asList("my_namespace", "my_table"))
+        .build()) {
+    System.out.println("Rows: " + dataset.countRows());
+}
+```
+
+Do not call `describeTable()` and then open the returned location with `Dataset.open(uri)`.
+Opening through `namespaceClient()` is what applies the vended storage options and enables
+automatic credential refresh. No object store credentials need to be passed by the application.
+
 ## Metadata Operations
 
 ### Creating a Namespace Path

docs/src/js/classes/Connection.md

@@ -386,6 +386,29 @@ Drop an existing table.
 
 ***
 
+### dropTableAsync()
+
+```ts
+abstract dropTableAsync(name, namespacePath?): Promise<Job>
+```
+
+Start dropping a table and return its cleanup job.
+
+The table may become unavailable before its data files are removed. Wait
+on the returned job to know when cleanup has finished.
+
+#### Parameters
+
+* **name**: `string`
+
+* **namespacePath?**: `string`[]
+
+#### Returns
+
+`Promise`&lt;[`Job`](Job.md)&gt;
+
+***
+
 ### getJob()
 
 ```ts

docs/src/js/classes/Table.md

@@ -69,14 +69,34 @@ abstract addColumns(newColumnTransforms): Promise<AddColumnsResult>
 
 Add new columns with defined values.
 
+The `{ computed }` form stores the expression rather than evaluating it
+now: the column is committed with no values, and rows get them from
+[Table#refreshColumn](Table.md#refreshcolumn). Declaring one therefore costs the same on a
+large table as on an empty one.
+
+A refresh does not revisit rows it has already filled, so mutating an
+input leaves the value computed at fill time; recomputing means dropping
+the column and declaring it again. While a declaration reads a column,
+that column cannot be renamed, retyped or dropped.
+
+On LanceDB Cloud and Enterprise the expression is planned by the
+server, and the refresh runs as a server job -- see
+[Table#refreshColumnAsync](Table.md#refreshcolumnasync).
+
 #### Parameters
 
-* **newColumnTransforms**: `Field`&lt;`any`&gt; \| `Field`&lt;`any`&gt;[] \| `Schema`&lt;`any`&gt; \| [`AddColumnsSql`](../interfaces/AddColumnsSql.md)[]
+* **newColumnTransforms**:
+    \| `Field`&lt;`any`&gt;
+    \| `Field`&lt;`any`&gt;[]
+    \| `Schema`&lt;`any`&gt;
+    \| [`AddColumnsSql`](../interfaces/AddColumnsSql.md)[]
+    \| `object`
     Either:
     - An array of objects with column names and SQL expressions to calculate values
     - A single Arrow Field defining one column with its data type (column will be initialized with null values)
     - An array of Arrow Fields defining columns with their data types (columns will be initialized with null values)
     - An Arrow Schema defining columns with their data types (columns will be initialized with null values)
+    - `{ computed }`, declaring columns defined by a SQL expression whose type and inputs are derived from it
 
 #### Returns
 
@@ -85,6 +105,13 @@ Add new columns with defined values.
 A promise that resolves to an object
 containing the new version number of the table after adding the columns.
 
+#### Example
+
+```ts
+await table.addColumns({ computed: [{ name: "doubled", valueSql: "x * 2" }] });
+const { rowsFilled } = await table.refreshColumn("doubled");
+```
+
 ***
 
 ### alterColumns()
@@ -186,6 +213,39 @@ version of the table.
 
 ***
 
+### checkpointLsm()
+
+```ts
+abstract checkpointLsm(): Promise<void>
+```
+
+Converge this table's LSM write path into its base table.
+
+Seals once, then triggers compaction and polls until the L0 that existed
+at the start is gone. The target set is fixed at the start, so
+generations created *during* the checkpoint are ignored — that is what
+lets it terminate under write load, and what makes it best-effort: it
+converges the fresh tier as of some instant. Idempotent, abandonable at
+any point, and safe to run on a cadence.
+
+There is no liveness bound — the compactor pool is shared across tables,
+so a checkpoint queued behind unrelated work looks exactly like one that
+is merging. The caller owns the deadline.
+
+#### Returns
+
+`Promise`&lt;`void`&gt;
+
+#### Example
+
+```ts
+const before = await table.getLsmStats();
+await table.checkpointLsm();
+const after = await table.getLsmStats();
+```
+
+***
+
 ### close()
 
 ```ts
@@ -223,6 +283,24 @@ It is a no-op when no writers are cached.
 
 ***
 
+### compactLsm()
+
+```ts
+abstract compactLsm(): Promise<void>
+```
+
+Trigger a background L0 → base compaction pass per bucket.
+
+Returns once the passes are *dispatched*, not once they finish — watch
+[Table#getLsmStats](Table.md#getlsmstats) for progress, or use
+[Table#checkpointLsm](Table.md#checkpointlsm) to wait for convergence.
+
+#### Returns
+
+`Promise`&lt;`void`&gt;
+
+***
+
 ### countRows()
 
 ```ts
@@ -421,6 +499,48 @@ Drop an index from the table.
 
 ***
 
+### flushLsm()
+
+```ts
+abstract flushLsm(): Promise<void>
+```
+
+Seal every bucket's active memtable into a new L0 generation.
+
+Returns once the seal is committed. Sealing an empty memtable is a no-op,
+so this is safe to call repeatedly.
+
+#### Returns
+
+`Promise`&lt;`void`&gt;
+
+***
+
+### getLsmStats()
+
+```ts
+abstract getLsmStats(includeGenerationRows?): Promise<undefined | LsmStats>
+```
+
+Read live per-bucket LSM state.
+
+Answers "how far behind is my fresh tier", "which bucket is hot", and
+"why is my fresh-tier vector search brute-force". Mutates no table state.
+
+Resolves to `undefined` only when the LSM write path is not enabled.
+
+#### Parameters
+
+* **includeGenerationRows?**: `boolean`
+    Also count rows per L0 generation.
+    Off by default because each count opens an uncached Lance dataset.
+
+#### Returns
+
+`Promise`&lt;`undefined` \| [`LsmStats`](../interfaces/LsmStats.md)&gt;
+
+***
+
 ### getLsmWriteSpec()
 
 ```ts
@@ -431,9 +551,10 @@ Read the [LsmWriteSpec](../interfaces/LsmWriteSpec.md) currently installed on th
 
 Resolves to `undefined` when the MemWAL LSM write path is not enabled (no
 spec has been set, or it was removed with [Table#unsetLsmWriteSpec](Table.md#unsetlsmwritespec)).
-The returned spec — including its `maintainedIndexes` and
-`writerConfigDefaults` — mirrors what was passed to
-[Table#setLsmWriteSpec](Table.md#setlsmwritespec).
+The returned spec mirrors what was passed to
+[Table#setLsmWriteSpec](Table.md#setlsmwritespec), except that `maintainedIndexes` always
+reports the concrete list resolved when the spec was set — `undefined`
+never round-trips.
 
 #### Returns
 
@@ -717,6 +838,67 @@ for await (const batch of table.query()) {
 
 ***
 
+### refreshColumn()
+
+```ts
+abstract refreshColumn(column): Promise<RefreshColumnResult>
+```
+
+Fill the rows of a computed column that hold no value yet.
+
+Rows appended since the last refresh are filled by the next one; rows
+already filled are left as they are, so the call is idempotent and does
+not observe a mutated input. Local tables only: a remote refresh runs
+as a server job, through [Table#refreshColumnAsync](Table.md#refreshcolumnasync).
+
+#### Parameters
+
+* **column**: `string`
+    The name of the computed column to fill.
+
+#### Returns
+
+`Promise`&lt;[`RefreshColumnResult`](../interfaces/RefreshColumnResult.md)&gt;
+
+A promise that resolves to the
+number of rows filled and the new version number of the table.
+
+***
+
+### refreshColumnAsync()
+
+```ts
+abstract refreshColumnAsync(column): Promise<Job>
+```
+
+Like [Table#refreshColumn](Table.md#refreshcolumn), but returns a handle to the refresh
+job instead of blocking until it completes.
+
+The job may already be complete when returned; callers must not assume
+the column is filled until [Job.wait](Job.md#wait) resolves. Invalid input --
+an unknown column, or one that is not computed -- rejects here rather
+than failing the job. On local tables the job runs in-process; on
+LanceDB Cloud and Enterprise it is the server's backfill job.
+
+#### Parameters
+
+* **column**: `string`
+    The name of the computed column to fill.
+
+#### Returns
+
+`Promise`&lt;[`Job`](Job.md)&gt;
+
+#### Example
+
+```ts
+const job = await table.refreshColumnAsync("doubled");
+await job.wait();
+console.log(await job.status()); // "finished"
+```
+
+***
+
 ### restore()
 
 ```ts
@@ -806,6 +988,11 @@ All variants require the table to have an unenforced primary key
 ([Table#setUnenforcedPrimaryKey](Table.md#setunenforcedprimarykey)); bucket sharding additionally
 requires it to be the single column being bucketed.
 
+Omitting `maintainedIndexes` maintains every index on the table, resolved
+here, failing if one cannot be maintained — name them to install anyway.
+Naming them pins an exact set, and a still-building index is rejected
+rather than quietly omitted.
+
 #### Parameters
 
 * **spec**: [`LsmWriteSpec`](../interfaces/LsmWriteSpec.md)

docs/src/js/globals.md

@@ -58,6 +58,7 @@
 - [BranchDiff](interfaces/BranchDiff.md)
 - [BranchIndexSummary](interfaces/BranchIndexSummary.md)
 - [BranchRowCountSummary](interfaces/BranchRowCountSummary.md)
+- [BucketStats](interfaces/BucketStats.md)
 - [ClientConfig](interfaces/ClientConfig.md)
 - [ColumnAlteration](interfaces/ColumnAlteration.md)
 - [ColumnOrdering](interfaces/ColumnOrdering.md)
@@ -81,6 +82,7 @@
 - [FtsToken](interfaces/FtsToken.md)
 - [FullTextQuery](interfaces/FullTextQuery.md)
 - [FullTextSearchOptions](interfaces/FullTextSearchOptions.md)
+- [GenerationStats](interfaces/GenerationStats.md)
 - [HnswPqOptions](interfaces/HnswPqOptions.md)
 - [HnswSqOptions](interfaces/HnswSqOptions.md)
 - [IndexConfig](interfaces/IndexConfig.md)
@@ -94,7 +96,9 @@
 - [JobInfo](interfaces/JobInfo.md)
 - [ListNamespacesOptions](interfaces/ListNamespacesOptions.md)
 - [ListNamespacesResponse](interfaces/ListNamespacesResponse.md)
+- [LsmStats](interfaces/LsmStats.md)
 - [LsmWriteSpec](interfaces/LsmWriteSpec.md)
+- [MemtableStats](interfaces/MemtableStats.md)
 - [MergeBlocker](interfaces/MergeBlocker.md)
 - [MergeBranchResult](interfaces/MergeBranchResult.md)
 - [MergePreview](interfaces/MergePreview.md)
@@ -105,6 +109,7 @@
 - [OptimizeOptions](interfaces/OptimizeOptions.md)
 - [OptimizeStats](interfaces/OptimizeStats.md)
 - [QueryExecutionOptions](interfaces/QueryExecutionOptions.md)
+- [RefreshColumnResult](interfaces/RefreshColumnResult.md)
 - [RemovalStats](interfaces/RemovalStats.md)
 - [RenameTableOptions](interfaces/RenameTableOptions.md)
 - [RestNamespaceConfig](interfaces/RestNamespaceConfig.md)

docs/src/js/interfaces/BucketStats.md

@@ -0,0 +1,116 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / BucketStats
+
+# Interface: BucketStats
+
+Live state of one bucket. A table is N buckets on one node; flattening to a
+single number hides the one hot bucket that is usually why someone opened
+this endpoint.
+
+## Properties
+
+### compacting
+
+```ts
+compacting: boolean;
+```
+
+Whether a pass owns this bucket's compaction latch right now. Says *a*
+driver is running, not *whose*, and the latch is held from dispatch —
+including while the pass queues for a pod-wide compactor permit. Read it
+as "do not pile on", never as "mine is progressing".
+
+***
+
+### currentGeneration
+
+```ts
+currentGeneration: number;
+```
+
+The generation the active memtable will become.
+
+***
+
+### generations
+
+```ts
+generations: GenerationStats[];
+```
+
+Flushed L0 generations not yet merged into the base table.
+
+***
+
+### manifestVersion
+
+```ts
+manifestVersion: number;
+```
+
+Version of the shard manifest these numbers were read from.
+
+***
+
+### memtables?
+
+```ts
+optional memtables: MemtableStats[];
+```
+
+Oldest first, active last. Absent for a `"Sealed"` bucket, whose
+in-memory state is torn down.
+
+***
+
+### replayAfterWalEntryPosition
+
+```ts
+replayAfterWalEntryPosition: number;
+```
+
+WAL position replay resumes from.
+
+***
+
+### shardId
+
+```ts
+shardId: string;
+```
+
+The shard this bucket writes.
+
+***
+
+### status
+
+```ts
+status: string;
+```
+
+`"Active"` or `"Sealed"` (drop-table 2PC in flight).
+
+***
+
+### walEntryPositionLastSeen
+
+```ts
+walEntryPositionLastSeen: number;
+```
+
+Highest WAL position the writer has seen. The difference against
+`replayAfterWalEntryPosition` is the WAL lag.
+
+***
+
+### writerEpoch
+
+```ts
+writerEpoch: number;
+```
+
+Epoch of the writer that currently owns the shard.

docs/src/js/interfaces/GenerationStats.md

@@ -0,0 +1,40 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / GenerationStats
+
+# Interface: GenerationStats
+
+One flushed L0 generation.
+
+## Properties
+
+### bytes
+
+```ts
+bytes: number;
+```
+
+On-disk size of the generation.
+
+***
+
+### generation
+
+```ts
+generation: number;
+```
+
+The generation number. Increases as memtables are sealed into L0.
+
+***
+
+### rows?
+
+```ts
+optional rows: number;
+```
+
+Present only when `includeGenerationRows` was requested. Off by default
+because each count opens an uncached Lance dataset.

docs/src/js/interfaces/LsmStats.md

@@ -0,0 +1,22 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / LsmStats
+
+# Interface: LsmStats
+
+Live per-bucket LSM state, as returned by `Table#getLsmStats`.
+
+Nothing here is derived: sums and differences (total L0 bytes, WAL lag) are
+the caller's to compute.
+
+## Properties
+
+### buckets
+
+```ts
+buckets: BucketStats[];
+```
+
+One entry per bucket backing this table.

docs/src/js/interfaces/LsmWriteSpec.md

@@ -34,7 +34,9 @@ Bucket and identity variants: the sharding column.
 optional maintainedIndexes: string[];
 ```
 
-Names of indexes the MemWAL should keep up to date during writes.
+Indexes the MemWAL keeps up to date. Omit to maintain every supported
+index, resolved on install — a snapshot, so indexes created later are not
+maintained. Pass `[]` for none.
 
 ***
 

docs/src/js/interfaces/MemtableStats.md

@@ -0,0 +1,60 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / MemtableStats
+
+# Interface: MemtableStats
+
+One in-memory memtable.
+
+## Properties
+
+### batches
+
+```ts
+batches: number;
+```
+
+Record batches currently buffered.
+
+***
+
+### bytes
+
+```ts
+bytes: number;
+```
+
+Estimated in-memory size.
+
+***
+
+### generation
+
+```ts
+generation: number;
+```
+
+The generation this memtable will become once sealed.
+
+***
+
+### indexes
+
+```ts
+indexes: string[];
+```
+
+Names of the indexes this memtable carries. An absent name is the whole
+answer to "why is my fresh-tier search on that column brute-force".
+
+***
+
+### rows
+
+```ts
+rows: number;
+```
+
+Rows currently buffered.

docs/src/js/interfaces/RefreshColumnResult.md

@@ -0,0 +1,23 @@
+[**@lancedb/lancedb**](../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../globals.md) / RefreshColumnResult
+
+# Interface: RefreshColumnResult
+
+## Properties
+
+### rowsFilled
+
+```ts
+rowsFilled: number;
+```
+
+***
+
+### version
+
+```ts
+version: number;
+```

docs/src/js/interfaces/TableStatistics.md

@@ -44,4 +44,7 @@ The number of rows in the table
 totalBytes: number;
 ```
 
-The total number of bytes in the table
+The total size, in bytes, of the table's data files, index files, and
+overlay files
+
+Read from the manifest, so this excludes deletion files and manifests.

docs/src/js/namespaces/embedding/README.md

@@ -25,9 +25,12 @@
 ### Type Aliases
 
 - [CreateReturnType](type-aliases/CreateReturnType.md)
+- [EmbeddingMetadataEntry](type-aliases/EmbeddingMetadataEntry.md)
+- [ResolvedEmbeddingFunctionConfig](type-aliases/ResolvedEmbeddingFunctionConfig.md)
 
 ### Functions
 
 - [LanceSchema](functions/LanceSchema.md)
 - [getRegistry](functions/getRegistry.md)
+- [parseEmbeddingMetadata](functions/parseEmbeddingMetadata.md)
 - [register](functions/register.md)

docs/src/js/namespaces/embedding/functions/parseEmbeddingMetadata.md

@@ -0,0 +1,22 @@
+[**@lancedb/lancedb**](../../../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../../../globals.md) / [embedding](../README.md) / parseEmbeddingMetadata
+
+# Function: parseEmbeddingMetadata()
+
+```ts
+function parseEmbeddingMetadata(json): EmbeddingMetadataEntry[]
+```
+
+The single parser for `embedding_functions` schema metadata: every reader
+goes through here, so the wire contract cannot fork between them.
+
+## Parameters
+
+* **json**: `string`
+
+## Returns
+
+[`EmbeddingMetadataEntry`](../type-aliases/EmbeddingMetadataEntry.md)[]

docs/src/js/namespaces/embedding/type-aliases/EmbeddingMetadataEntry.md

@@ -0,0 +1,40 @@
+[**@lancedb/lancedb**](../../../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../../../globals.md) / [embedding](../README.md) / EmbeddingMetadataEntry
+
+# Type Alias: EmbeddingMetadataEntry
+
+```ts
+type EmbeddingMetadataEntry: object;
+```
+
+One entry of the `embedding_functions` schema metadata, with the column
+keys normalized across the bindings' spellings.
+
+## Type declaration
+
+### model
+
+```ts
+model: EmbeddingFunction["TOptions"];
+```
+
+### name
+
+```ts
+name: string;
+```
+
+### sourceColumn
+
+```ts
+sourceColumn: string;
+```
+
+### vectorColumn
+
+```ts
+vectorColumn: string;
+```

docs/src/js/namespaces/embedding/type-aliases/ResolvedEmbeddingFunctionConfig.md

@@ -0,0 +1,22 @@
+[**@lancedb/lancedb**](../../../README.md) • **Docs**
+
+***
+
+[@lancedb/lancedb](../../../globals.md) / [embedding](../README.md) / ResolvedEmbeddingFunctionConfig
+
+# Type Alias: ResolvedEmbeddingFunctionConfig
+
+```ts
+type ResolvedEmbeddingFunctionConfig: EmbeddingFunctionConfig & object;
+```
+
+An [EmbeddingFunctionConfig] read back from table metadata, where the
+vector column is always recorded.
+
+## Type declaration
+
+### vectorColumn
+
+```ts
+vectorColumn: string;
+```

docs/src/python/python.md

@@ -31,7 +31,7 @@ is also an [asynchronous API client](#connections-asynchronous).
 ## Namespaces (Synchronous)
 
 A namespace-backed connection resolves tables through a
-[Lance namespace](https://lancedb.github.io/lance-namespace/) service instead of
+[Lance namespace](https://lance-format.github.io/lance-namespace/) service instead of
 listing a storage directory.
 
 ::: lancedb.connect_namespace
@@ -52,6 +52,56 @@ listing a storage directory.
 
 ::: lancedb.table.Branches
 
+::: lancedb.LsmWriteSpec
+
+## Functions and Jobs
+
+::: lancedb.functions.FunctionArtifact
+
+::: lancedb.functions.FunctionParameter
+
+::: lancedb.functions.FunctionResultField
+
+::: lancedb.functions.FunctionOutput
+
+::: lancedb.functions.FunctionSignature
+
+::: lancedb.functions.PythonEnvironmentSpec
+
+::: lancedb.functions.udf
+
+::: lancedb.functions.UdfDefinition
+
+::: lancedb.functions.FunctionRegistrationRequest
+
+::: lancedb.functions.FunctionArtifactRequest
+
+::: lancedb.functions.FunctionArtifactContent
+
+::: lancedb.functions.PythonAdapterSpec
+
+::: lancedb.functions.FunctionVersion
+
+::: lancedb.functions.PythonRuntimeSpec
+
+::: lancedb.functions.FunctionVersionRef
+
+::: lancedb.functions.ApplicationInput
+
+::: lancedb.functions.FunctionApplication
+
+::: lancedb.functions.InputBinding
+
+::: lancedb.functions.OutputMapping
+
+::: lancedb.functions.FunctionBinding
+
+::: lancedb.functions.RefreshColumnResult
+
+::: lancedb.job.Job
+
+::: lancedb.job.AsyncJob
+
 ## Expressions
 
 Type-safe expression builder for filters and projections. Use these instead
@@ -151,8 +201,9 @@ The same option is available on `lancedb.tokenize(...)` and the deprecated
 ```python
 import lancedb
 
-tokens = list(lancedb.tokenize("acme makes searchable data",
-                               custom_stop_words=["acme"]))
+tokens = list(
+    lancedb.tokenize("acme makes searchable data", custom_stop_words=["acme"])
+)
 ```
 
 ::: lancedb.tokenize

java/README.md

@@ -29,6 +29,48 @@ LanceNamespace namespaceClient = LanceDbNamespaceClientBuilder.newBuilder()
     .build();
 ```
 
+## MemWAL LSM write path
+
+Most table operations reach LanceDB through the `LanceNamespace` above, which is
+generated from the Lance Namespace specification. The MemWAL LSM routes are not part
+of that specification, so they are issued through a separate client:
+
+```java
+import com.lancedb.LanceDbRestClient;
+import com.lancedb.LanceDbTableLsm;
+import com.lancedb.LsmWriteSpec;
+
+LanceDbRestClient client = LanceDbNamespaceClientBuilder.newBuilder()
+    .apiKey("your_lancedb_cloud_api_key")
+    .database("your_database_name")
+    .buildRestClient();
+
+LanceDbTableLsm lsm = new LanceDbTableLsm(client, "my_table");
+
+// Route future merge_insert upserts through the MemWAL, hash-bucketed by `id`.
+lsm.setLsmWriteSpec(LsmWriteSpec.bucket("id", 16));
+
+// ... merge_insert traffic ...
+
+// Converge the fresh tier into the base table.
+lsm.checkpointLsm();
+
+// Inspect live per-bucket state.
+lsm.getLsmStats().ifPresent(stats -> stats.buckets().forEach(bucket ->
+    System.out.println(bucket.shardId() + ": " + bucket.generations().size() + " L0 generations")));
+
+client.close();
+```
+
+`maintainedIndexes` is tri-state, and the null default is the opposite of what a Java
+reader usually expects:
+
+| Value | Meaning |
+| --- | --- |
+| unset (null) | Maintain **every** index the MemWAL can, resolved on install |
+| `Collections.emptyList()` | Maintain **none** |
+| `Arrays.asList("id_idx")` | Maintain exactly those |
+
 ## Development
 
 Build:

java/lancedb-core/pom.xml

@@ -8,7 +8,7 @@
     <parent>
       <groupId>com.lancedb</groupId>
       <artifactId>lancedb-parent</artifactId>
-      <version>0.37.1-beta.0</version>
+      <version>0.38.0-beta.3</version>
       <relativePath>../pom.xml</relativePath>
     </parent>
 
@@ -33,6 +33,20 @@
             <artifactId>arrow-memory-netty</artifactId>
         </dependency>
 
+        <!-- Transport for the LanceDB routes outside the Lance Namespace spec.
+             Versions match what lance-namespace-apache-client resolves to. -->
+        <dependency>
+            <groupId>org.apache.httpcomponents.client5</groupId>
+            <artifactId>httpclient5</artifactId>
+            <version>5.2.1</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.17.1</version>
+        </dependency>
+
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter</artifactId>

java/lancedb-core/src/main/java/com/lancedb/BucketStats.java

@@ -0,0 +1,194 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.OptionalLong;
+
+/**
+ * Live state of one bucket. A table is N buckets on one node; flattening to a single number hides
+ * the one hot bucket that is usually why someone opened this endpoint.
+ */
+public class BucketStats {
+  private static final String CONTEXT = "bucket stats";
+
+  private final String shardId;
+  private final String status;
+  private final long writerEpoch;
+  private final long manifestVersion;
+  private final long currentGeneration;
+  private final long replayAfterWalEntryPosition;
+  private final long walEntryPositionLastSeen;
+  private final List<GenerationStats> generations;
+  private final boolean compacting;
+  private final List<MemtableStats> memtables;
+
+  BucketStats(
+      String shardId,
+      String status,
+      long writerEpoch,
+      long manifestVersion,
+      long currentGeneration,
+      long replayAfterWalEntryPosition,
+      long walEntryPositionLastSeen,
+      List<GenerationStats> generations,
+      boolean compacting,
+      List<MemtableStats> memtables) {
+    this.shardId = shardId;
+    this.status = status;
+    this.writerEpoch = writerEpoch;
+    this.manifestVersion = manifestVersion;
+    this.currentGeneration = currentGeneration;
+    this.replayAfterWalEntryPosition = replayAfterWalEntryPosition;
+    this.walEntryPositionLastSeen = walEntryPositionLastSeen;
+    this.generations = Collections.unmodifiableList(generations);
+    this.compacting = compacting;
+    this.memtables = memtables == null ? null : Collections.unmodifiableList(memtables);
+  }
+
+  /** The shard this bucket writes. */
+  public String shardId() {
+    return shardId;
+  }
+
+  /** {@code "Active"} or {@code "Sealed"} (drop-table 2PC in flight). */
+  public String status() {
+    return status;
+  }
+
+  /** Epoch of the writer that currently owns the shard. */
+  public long writerEpoch() {
+    return writerEpoch;
+  }
+
+  /** Version of the shard manifest these numbers were read from. */
+  public long manifestVersion() {
+    return manifestVersion;
+  }
+
+  /** The generation the active memtable will become. */
+  public long currentGeneration() {
+    return currentGeneration;
+  }
+
+  /** WAL position replay resumes from. */
+  public long replayAfterWalEntryPosition() {
+    return replayAfterWalEntryPosition;
+  }
+
+  /**
+   * Highest WAL position the writer has seen. The difference against {@link
+   * #replayAfterWalEntryPosition()} is the WAL lag.
+   */
+  public long walEntryPositionLastSeen() {
+    return walEntryPositionLastSeen;
+  }
+
+  /** Flushed L0 generations not yet merged into the base table. */
+  public List<GenerationStats> generations() {
+    return generations;
+  }
+
+  /**
+   * Whether a pass owns this bucket's compaction latch right now. Says <em>a</em> driver is
+   * running, not <em>whose</em>, and the latch is held from dispatch — including while the pass
+   * queues for a pod-wide compactor permit. Read it as "do not pile on", never as "mine is
+   * progressing".
+   */
+  public boolean compacting() {
+    return compacting;
+  }
+
+  /** Oldest first, active last. Empty for a {@code "Sealed"} bucket, whose state is torn down. */
+  public Optional<List<MemtableStats>> memtables() {
+    return Optional.ofNullable(memtables);
+  }
+
+  /** The newest flushed generation, or empty when L0 is empty. */
+  OptionalLong newestGeneration() {
+    OptionalLong newest = OptionalLong.empty();
+    for (GenerationStats generation : generations) {
+      if (!newest.isPresent() || generation.generation() > newest.getAsLong()) {
+        newest = OptionalLong.of(generation.generation());
+      }
+    }
+    return newest;
+  }
+
+  /**
+   * How many generations at or below {@code target} are still in L0.
+   *
+   * <p>A count, not a boolean: one pass drains a bounded prefix rather than the whole target set,
+   * so a boolean would read as "no progress" for every pass but the last. Compaction drains
+   * oldest-first, so this decreases monotonically.
+   */
+  long outstandingGenerations(long target) {
+    long count = 0;
+    for (GenerationStats generation : generations) {
+      if (generation.generation() <= target) {
+        count++;
+      }
+    }
+    return count;
+  }
+
+  static BucketStats fromJson(JsonNode node) {
+    JsonFields.requiredObject(node, CONTEXT);
+    List<GenerationStats> generations = new ArrayList<GenerationStats>();
+    for (JsonNode generation : JsonFields.requiredArray(node, "generations", CONTEXT)) {
+      generations.add(GenerationStats.fromJson(generation));
+    }
+
+    JsonNode memtablesNode = JsonFields.optionalArray(node, "memtables", CONTEXT);
+    List<MemtableStats> memtables = null;
+    if (memtablesNode != null) {
+      memtables = new ArrayList<MemtableStats>();
+      for (JsonNode memtable : memtablesNode) {
+        memtables.add(MemtableStats.fromJson(memtable));
+      }
+    }
+
+    return new BucketStats(
+        JsonFields.requiredText(node, "shard_id", CONTEXT),
+        JsonFields.requiredText(node, "status", CONTEXT),
+        JsonFields.requiredLong(node, "writer_epoch", CONTEXT),
+        JsonFields.requiredLong(node, "manifest_version", CONTEXT),
+        JsonFields.requiredLong(node, "current_generation", CONTEXT),
+        JsonFields.requiredLong(node, "replay_after_wal_entry_position", CONTEXT),
+        JsonFields.requiredLong(node, "wal_entry_position_last_seen", CONTEXT),
+        generations,
+        JsonFields.requiredBoolean(node, "compacting", CONTEXT),
+        memtables);
+  }
+
+  @Override
+  public String toString() {
+    return "BucketStats{shardId="
+        + shardId
+        + ", status="
+        + status
+        + ", currentGeneration="
+        + currentGeneration
+        + ", generations="
+        + generations
+        + ", compacting="
+        + compacting
+        + "}";
+  }
+}

java/lancedb-core/src/main/java/com/lancedb/GenerationStats.java

@@ -0,0 +1,64 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.util.OptionalLong;
+
+/** One flushed L0 generation. */
+public class GenerationStats {
+  private static final String CONTEXT = "generation stats";
+
+  private final long generation;
+  private final long bytes;
+  private final Long rows;
+
+  GenerationStats(long generation, long bytes, Long rows) {
+    this.generation = generation;
+    this.bytes = bytes;
+    this.rows = rows;
+  }
+
+  /** The generation number. Increases as memtables are sealed into L0. */
+  public long generation() {
+    return generation;
+  }
+
+  /** On-disk size of the generation. */
+  public long bytes() {
+    return bytes;
+  }
+
+  /**
+   * Rows in this generation, present only when {@code includeGenerationRows} was requested. Off by
+   * default because each count opens an uncached Lance dataset.
+   */
+  public OptionalLong rows() {
+    return rows == null ? OptionalLong.empty() : OptionalLong.of(rows);
+  }
+
+  static GenerationStats fromJson(JsonNode node) {
+    JsonFields.requiredObject(node, CONTEXT);
+    return new GenerationStats(
+        JsonFields.requiredLong(node, "generation", CONTEXT),
+        JsonFields.requiredLong(node, "bytes", CONTEXT),
+        JsonFields.optionalLong(node, "rows", CONTEXT));
+  }
+
+  @Override
+  public String toString() {
+    return "GenerationStats{generation=" + generation + ", bytes=" + bytes + ", rows=" + rows + "}";
+  }
+}

java/lancedb-core/src/main/java/com/lancedb/JsonFields.java

@@ -0,0 +1,109 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+/**
+ * Strict readers for decoding LanceDB JSON responses.
+ *
+ * <p>Every reader fails closed: a missing, null, or wrong-typed field throws rather than
+ * defaulting. That mirrors the serde decoding the Rust client applies to the same payloads in
+ * {@code rust/lancedb/src/table/lsm_stats.rs}, where a required field has no default and a
+ * malformed response is an error rather than a zero.
+ *
+ * <p>The alternative — Jackson's {@code path()}, which yields a missing node that reads as an empty
+ * array or a zero — is unsafe here because {@link LanceDbTableLsm#checkpointLsm()} decides
+ * convergence from these numbers. A defaulted {@code generations} array is indistinguishable from a
+ * drained one, so a malformed response would report a checkpoint that never happened.
+ */
+final class JsonFields {
+  private JsonFields() {}
+
+  /** The node itself, once confirmed to be a JSON object. */
+  static JsonNode requiredObject(JsonNode node, String context) {
+    if (node == null || !node.isObject()) {
+      throw new IllegalStateException(context + " is not a JSON object: " + node);
+    }
+    return node;
+  }
+
+  static String requiredText(JsonNode owner, String field, String context) {
+    JsonNode value = required(owner, field, context);
+    if (!value.isTextual()) {
+      throw new IllegalStateException(fieldIs(context, field, "a string", value));
+    }
+    return value.asText();
+  }
+
+  static long requiredLong(JsonNode owner, String field, String context) {
+    JsonNode value = required(owner, field, context);
+    if (!value.isIntegralNumber()) {
+      throw new IllegalStateException(fieldIs(context, field, "an integer", value));
+    }
+    return value.asLong();
+  }
+
+  static boolean requiredBoolean(JsonNode owner, String field, String context) {
+    JsonNode value = required(owner, field, context);
+    if (!value.isBoolean()) {
+      throw new IllegalStateException(fieldIs(context, field, "a boolean", value));
+    }
+    return value.asBoolean();
+  }
+
+  static JsonNode requiredArray(JsonNode owner, String field, String context) {
+    JsonNode value = required(owner, field, context);
+    if (!value.isArray()) {
+      throw new IllegalStateException(fieldIs(context, field, "an array", value));
+    }
+    return value;
+  }
+
+  /** Null when the field is absent or JSON null, mirroring a serde {@code Option}. */
+  static Long optionalLong(JsonNode owner, String field, String context) {
+    JsonNode value = owner.get(field);
+    if (value == null || value.isNull()) {
+      return null;
+    }
+    if (!value.isIntegralNumber()) {
+      throw new IllegalStateException(fieldIs(context, field, "an integer", value));
+    }
+    return value.asLong();
+  }
+
+  /** Null when the field is absent or JSON null, mirroring a serde {@code Option}. */
+  static JsonNode optionalArray(JsonNode owner, String field, String context) {
+    JsonNode value = owner.get(field);
+    if (value == null || value.isNull()) {
+      return null;
+    }
+    if (!value.isArray()) {
+      throw new IllegalStateException(fieldIs(context, field, "an array", value));
+    }
+    return value;
+  }
+
+  private static JsonNode required(JsonNode owner, String field, String context) {
+    JsonNode value = owner.get(field);
+    if (value == null || value.isNull()) {
+      throw new IllegalStateException(context + " is missing required field '" + field + "'");
+    }
+    return value;
+  }
+
+  private static String fieldIs(String context, String field, String expected, JsonNode value) {
+    return context + " field '" + field + "' is not " + expected + ": " + value;
+  }
+}

java/lancedb-core/src/main/java/com/lancedb/LanceDbNamespaceClientBuilder.java

@@ -136,29 +136,48 @@ public class LanceDbNamespaceClientBuilder {
    * @throws IllegalStateException if required parameters are missing
    */
   public LanceNamespace build() {
-    // Validate required fields
+    validate();
+
+    // Build configuration map
+    Map<String, String> config = new HashMap<>(additionalConfig);
+    config.put("header.x-lancedb-database", database);
+    config.put("header.x-api-key", apiKey);
+    config.put("uri", resolveUri());
+
+    return LanceNamespace.connect("rest", config, null);
+  }
+
+  /**
+   * Build a {@link LanceDbRestClient} for the same endpoint.
+   *
+   * <p>Needed only for LanceDB routes that the Lance Namespace specification does not cover — the
+   * MemWAL LSM write path, reached through {@link LanceDbTableLsm}. Every other table operation
+   * belongs on the {@link LanceNamespace} from {@link #build()}.
+   *
+   * <p>The returned client owns an HTTP connection pool; close it when you are done with it.
+   *
+   * @return A configured LanceDbRestClient
+   * @throws IllegalStateException if required parameters are missing
+   */
+  public LanceDbRestClient buildRestClient() {
+    validate();
+    return new LanceDbRestClient(resolveUri(), apiKey, database);
+  }
+
+  private void validate() {
     if (apiKey == null) {
       throw new IllegalStateException("API key is required");
     }
     if (database == null) {
       throw new IllegalStateException("Database is required");
     }
+  }
 
-    // Build configuration map
-    Map<String, String> config = new HashMap<>(additionalConfig);
-    config.put("header.x-lancedb-database", database);
-    config.put("header.x-api-key", apiKey);
-
-    // Determine base URL
-    String uri;
+  /** The custom endpoint when set, else the LanceDB Cloud URL for this database and region. */
+  private String resolveUri() {
     if (endpoint.isPresent()) {
-      uri = endpoint.get();
-    } else {
-      String effectiveRegion = region.orElse(DEFAULT_REGION);
-      uri = String.format(CLOUD_URL_PATTERN, database, effectiveRegion);
+      return endpoint.get();
     }
-    config.put("uri", uri);
-
-    return LanceNamespace.connect("rest", config, null);
+    return String.format(CLOUD_URL_PATTERN, database, region.orElse(DEFAULT_REGION));
   }
 }

java/lancedb-core/src/main/java/com/lancedb/LanceDbRestClient.java

@@ -0,0 +1,119 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.hc.client5.http.classic.methods.HttpPost;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.HttpClients;
+import org.apache.hc.core5.http.ContentType;
+import org.apache.hc.core5.http.io.entity.EntityUtils;
+import org.apache.hc.core5.http.io.entity.StringEntity;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+
+/**
+ * Minimal HTTP client for LanceDB Cloud and Enterprise routes that the Lance Namespace
+ * specification does not cover.
+ *
+ * <p>Most table operations reach LanceDB through {@link org.lance.namespace.LanceNamespace}, which
+ * is generated from the namespace spec. A handful of routes — the MemWAL LSM write path in
+ * particular — are served by the same endpoint but are not part of that spec, so they are issued
+ * directly here. See {@link LanceDbTableLsm}.
+ *
+ * <p>Obtain one from {@link LanceDbNamespaceClientBuilder#buildRestClient()}.
+ */
+public class LanceDbRestClient implements Closeable {
+  private static final ObjectMapper MAPPER = new ObjectMapper();
+
+  private final String baseUri;
+  private final String apiKey;
+  private final String database;
+  private final CloseableHttpClient http;
+
+  LanceDbRestClient(String baseUri, String apiKey, String database) {
+    this.baseUri = baseUri.endsWith("/") ? baseUri.substring(0, baseUri.length() - 1) : baseUri;
+    this.apiKey = apiKey;
+    this.database = database;
+    // Automatic retries off, deliberately. The default strategy retries 429 and 503 —
+    // exactly the two statuses LanceDbTableLsm.checkpointLsm() acts on — which would
+    // silently double its explicit retry budget and would also retry compact_lsm in
+    // place, where the loop is designed to fall through to a fresh stats poll instead.
+    // The checkpoint loop owns the 421/429/503 transitions; the transport must not.
+    this.http = HttpClients.custom().disableAutomaticRetries().build();
+  }
+
+  /**
+   * POST {@code path}, sending {@code body} as JSON when it is non-null.
+   *
+   * @param path Absolute request path, beginning with {@code /}.
+   * @param body Object to serialize as the request body, or null to send no body.
+   * @return The parsed response body, or null when the response carried no content.
+   * @throws HttpException if the server returned a non-2xx status.
+   */
+  public JsonNode post(String path, Object body) {
+    HttpPost request = new HttpPost(baseUri + path);
+    request.setHeader("x-api-key", apiKey);
+    request.setHeader("x-lancedb-database", database);
+    try {
+      if (body != null) {
+        request.setEntity(
+            new StringEntity(MAPPER.writeValueAsString(body), ContentType.APPLICATION_JSON));
+      }
+      return http.execute(
+          request,
+          response -> {
+            String text =
+                response.getEntity() == null ? "" : EntityUtils.toString(response.getEntity());
+            int status = response.getCode();
+            if (status < 200 || status >= 300) {
+              throw new HttpException(status, "LanceDB request to " + path + " failed: " + text);
+            }
+            return text.isEmpty() ? null : MAPPER.readTree(text);
+          });
+    } catch (IOException e) {
+      throw new UncheckedIOException("LanceDB request to " + path + " failed", e);
+    }
+  }
+
+  @Override
+  public void close() throws IOException {
+    http.close();
+  }
+
+  /**
+   * A non-2xx response.
+   *
+   * <p>The status is exposed because callers act on it: {@link LanceDbTableLsm#checkpointLsm()}
+   * treats 429 and 503 as retryable and 421 as a lost node claim.
+   */
+  public static class HttpException extends RuntimeException {
+    private static final long serialVersionUID = 1L;
+
+    private final int statusCode;
+
+    public HttpException(int statusCode, String message) {
+      super(message);
+      this.statusCode = statusCode;
+    }
+
+    /** The HTTP status the failed response carried. */
+    public int statusCode() {
+      return statusCode;
+    }
+  }
+}

java/lancedb-core/src/main/java/com/lancedb/LanceDbTableLsm.java

@@ -0,0 +1,394 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.OptionalLong;
+
+/**
+ * The MemWAL LSM write path for one LanceDB Cloud or Enterprise table.
+ *
+ * <p>Installing an {@link LsmWriteSpec} routes {@code mergeInsert} upserts through Lance's MemWAL —
+ * an LSM-style append — instead of the standard merge path. Rows land in an in-memory memtable,
+ * seal into L0 generations, and are merged into the base table by compaction.
+ *
+ * <p>These routes are not part of the Lance Namespace specification, so they are issued directly
+ * rather than through {@link org.lance.namespace.LanceNamespace}.
+ *
+ * <pre>{@code
+ * LanceDbRestClient client = LanceDbNamespaceClientBuilder.newBuilder()
+ *     .apiKey("your_lancedb_cloud_api_key")
+ *     .database("your_database_name")
+ *     .buildRestClient();
+ *
+ * LanceDbTableLsm lsm = new LanceDbTableLsm(client, "my_table");
+ * lsm.setLsmWriteSpec(LsmWriteSpec.bucket("id", 16));
+ * // ... merge_insert traffic ...
+ * lsm.checkpointLsm();
+ * }</pre>
+ */
+public class LanceDbTableLsm {
+
+  /**
+   * Interval between {@code get_lsm_stats} polls during a checkpoint. One interval is roughly one
+   * compaction pass, the granularity at which the answer can change.
+   */
+  private static final long POLL_INTERVAL_MS = 5_000L;
+
+  /**
+   * Cap on re-issues from {@code flushLsm} after a 421, so a crash-looping node cannot turn flush →
+   * compact → 421 → flush into a spin.
+   *
+   * <p>Deliberately not shared with {@link #MAX_RETRIES}: a claim that keeps evaporating is a
+   * broken node, while contention is routine and wants a real budget.
+   */
+  private static final int MAX_REISSUES = 3;
+
+  /**
+   * Retryable faults tolerated on a <em>single</em> request, reset on every success — scattered
+   * contention across a long checkpoint must not accumulate toward a cap.
+   */
+  private static final int MAX_RETRIES = 8;
+
+  private static final long RETRY_BACKOFF_BASE_MS = 100L;
+  private static final long RETRY_BACKOFF_MAX_MS = 5_000L;
+
+  private final LanceDbRestClient client;
+  private final String tableIdentifier;
+
+  /**
+   * Bind the LSM routes for one table.
+   *
+   * @param client Transport for the LanceDB endpoint.
+   * @param tableIdentifier The table's full identifier, {@code $}-delimited when it sits inside a
+   *     namespace, such as {@code analytics$events}.
+   */
+  public LanceDbTableLsm(LanceDbRestClient client, String tableIdentifier) {
+    if (client == null) {
+      throw new IllegalArgumentException("Client cannot be null");
+    }
+    if (tableIdentifier == null || tableIdentifier.trim().isEmpty()) {
+      throw new IllegalArgumentException("Table identifier cannot be null or empty");
+    }
+    this.client = client;
+    this.tableIdentifier = tableIdentifier;
+  }
+
+  /**
+   * Install an {@link LsmWriteSpec} on this table, selecting the MemWAL LSM write path for future
+   * {@code mergeInsert} calls.
+   *
+   * <p>All variants require the table to have an unenforced primary key; bucket sharding
+   * additionally requires it to be the single column being bucketed.
+   */
+  public void setLsmWriteSpec(LsmWriteSpec spec) {
+    if (spec == null) {
+      throw new IllegalArgumentException("Spec cannot be null");
+    }
+    client.post(route("set_lsm_write_spec"), spec.toRequestBody());
+  }
+
+  /**
+   * Remove the {@link LsmWriteSpec} from this table, reverting to the standard {@code mergeInsert}
+   * write path.
+   *
+   * <p>Errors if no spec is currently set.
+   */
+  public void unsetLsmWriteSpec() {
+    client.post(route("unset_lsm_write_spec"), null);
+  }
+
+  /**
+   * Read the {@link LsmWriteSpec} currently installed on this table.
+   *
+   * <p>Empty when the LSM write path is not enabled. The returned spec mirrors what was installed,
+   * except that {@link LsmWriteSpec#maintainedIndexes()} always reports the concrete list resolved
+   * when the spec was set — a null selection never round-trips.
+   */
+  public Optional<LsmWriteSpec> getLsmWriteSpec() {
+    JsonNode response = client.post(route("get_lsm_write_spec"), null);
+    if (response == null || !response.hasNonNull("lsm_write_spec")) {
+      return Optional.empty();
+    }
+    return Optional.of(LsmWriteSpec.fromJson(response.get("lsm_write_spec")));
+  }
+
+  /**
+   * Seal every bucket's active memtable into a new L0 generation.
+   *
+   * <p>Returns once the seal is committed. Sealing an empty memtable is a no-op, so this is safe to
+   * call repeatedly.
+   */
+  public void flushLsm() {
+    client.post(route("flush_lsm"), null);
+  }
+
+  /**
+   * Trigger a background L0 → base compaction pass per bucket.
+   *
+   * <p>Returns once the passes are <em>dispatched</em>, not once they finish — watch {@link
+   * #getLsmStats}, or use {@link #checkpointLsm} to wait for convergence.
+   */
+  public void compactLsm() {
+    client.post(route("compact_lsm"), null);
+  }
+
+  /**
+   * Read live per-bucket LSM state.
+   *
+   * <p>Answers "how far behind is my fresh tier", "which bucket is hot", and "why is my fresh-tier
+   * vector search brute-force". Mutates no table state.
+   *
+   * <p>Empty only when the LSM write path is not enabled — that is, when the server sends an absent
+   * or null {@code lsm_stats}. A stats object that is present is decoded strictly, and a malformed
+   * one throws rather than decoding to something empty, because {@link #checkpointLsm} reads
+   * convergence out of these numbers and cannot tell a defaulted array from a drained one.
+   *
+   * @param includeGenerationRows Also count rows per L0 generation. Off by default because each
+   *     count opens an uncached Lance dataset.
+   * @throws IllegalStateException if the response is absent or does not decode.
+   */
+  public Optional<LsmStats> getLsmStats(boolean includeGenerationRows) {
+    Map<String, Object> body = new LinkedHashMap<String, Object>();
+    body.put("include_generation_rows", includeGenerationRows);
+    JsonNode response = client.post(route("get_lsm_stats"), body);
+    if (response == null) {
+      throw new IllegalStateException("get_lsm_stats returned an empty response body");
+    }
+    JsonNode stats = response.get("lsm_stats");
+    if (stats == null || stats.isNull()) {
+      return Optional.empty();
+    }
+    return Optional.of(LsmStats.fromJson(stats));
+  }
+
+  /** Equivalent to {@code getLsmStats(false)}. */
+  public Optional<LsmStats> getLsmStats() {
+    return getLsmStats(false);
+  }
+
+  /**
+   * Converge this table's LSM write path into its base table.
+   *
+   * <p>Seals once, fixes a target watermark from the resulting L0, then triggers compaction and
+   * polls until that L0 is gone. The target set is fixed at the start, so generations created
+   * <em>during</em> the checkpoint are ignored — that is what lets it terminate under write load,
+   * and what makes it best-effort: it converges the fresh tier as of some instant. Idempotent,
+   * abandonable at any point, safe on a cadence.
+   *
+   * <p>The loop runs here, not on the server: {@link #compactLsm} dispatches a pass and returns, so
+   * nothing holds a socket and a client can vanish mid-operation with nothing to reconcile.
+   * Completion is read from generation numbers in the shard manifest — durable state, unlike a
+   * count in a compact response, which a concurrent write invalidates.
+   *
+   * <p>No liveness bound — the caller owns the deadline. The compactor pool is shared across
+   * tables, so a checkpoint queued behind unrelated work looks exactly like one that is merging.
+   */
+  public void checkpointLsm() {
+    for (int reissue = 0; reissue <= MAX_REISSUES; reissue++) {
+      // The seal turns everything written before this call into a generation, so the
+      // watermark has to be read after it. Idempotent: sealing an empty memtable is a
+      // no-op, so a re-issue does not churn empty generations.
+      if (issueVoid(this::flushLsm)) {
+        backoff(reissue);
+        continue;
+      }
+
+      Attempt<Optional<LsmStats>> stats = issue(() -> getLsmStats(false));
+      if (stats.lostClaim) {
+        backoff(reissue);
+        continue;
+      }
+      if (!stats.value.isPresent()) {
+        // Not WAL-backed; flushLsm would have errored first but for a race.
+        return;
+      }
+
+      Map<String, Long> targets = newestGenerations(stats.value.get());
+      if (targets.isEmpty()) {
+        return;
+      }
+
+      if (drainToTargets(targets)) {
+        return;
+      }
+      backoff(reissue);
+    }
+    throw new IllegalStateException(
+        "checkpointLsm: the owning node kept losing its claim; re-issued from flush the maximum "
+            + "number of times");
+  }
+
+  /**
+   * Trigger and poll until no bucket holds a generation at or below its target.
+   *
+   * @return true when the drain finished, false when the table needs re-claiming from flush.
+   */
+  private boolean drainToTargets(Map<String, Long> targets) {
+    while (true) {
+      Attempt<Optional<LsmStats>> stats = issue(() -> getLsmStats(false));
+      if (stats.lostClaim) {
+        return false;
+      }
+      if (!stats.value.isPresent()) {
+        return true;
+      }
+
+      // `compacting` is the bucket's compaction latch, held from dispatch until the pass
+      // ends — including while it waits on a pod-wide permit. So it answers one question
+      // only: do not pile on. Buckets with nothing outstanding are skipped, not counted
+      // as idle.
+      long outstanding = 0;
+      boolean allCompacting = true;
+      for (BucketStats bucket : stats.value.get().buckets()) {
+        Long target = targets.get(bucket.shardId());
+        if (target == null) {
+          continue;
+        }
+        long remaining = bucket.outstandingGenerations(target);
+        if (remaining > 0) {
+          outstanding += remaining;
+          allCompacting &= bucket.compacting();
+        }
+      }
+      if (outstanding == 0) {
+        return true;
+      }
+
+      if (!allCompacting) {
+        try {
+          compactLsm();
+        } catch (LanceDbRestClient.HttpException e) {
+          if (isLostClaim(e)) {
+            return false;
+          }
+          if (!isRetryable(e)) {
+            throw e;
+          }
+          // A 429 here means the server could latch no bucket at all, which the poll
+          // above already handles. Not retried in place: the latch it would contend for
+          // is the one doing the work, so fall through and re-read — POLL_INTERVAL_MS is
+          // the backoff.
+        }
+      }
+      sleep(POLL_INTERVAL_MS);
+    }
+  }
+
+  /** The newest generation held by each bucket, skipping buckets holding none. */
+  private static Map<String, Long> newestGenerations(LsmStats stats) {
+    Map<String, Long> targets = new HashMap<String, Long>();
+    for (BucketStats bucket : stats.buckets()) {
+      OptionalLong newest = bucket.newestGeneration();
+      if (newest.isPresent()) {
+        targets.put(bucket.shardId(), newest.getAsLong());
+      }
+    }
+    return targets;
+  }
+
+  /**
+   * 429 (latch held, pool saturated, or the pod replaying its WAL) and 503 (a draining node, or a
+   * proxy between here and it).
+   */
+  private static boolean isRetryable(LanceDbRestClient.HttpException e) {
+    return e.statusCode() == 429 || e.statusCode() == 503;
+  }
+
+  /**
+   * 421: the owning node holds no claim. Only {@code flush} re-claims and replays, so this cannot
+   * be retried in place — the caller has to start over.
+   */
+  private static boolean isLostClaim(LanceDbRestClient.HttpException e) {
+    return e.statusCode() == 421;
+  }
+
+  /**
+   * Issue one LSM request, retrying in place while the fault is retryable.
+   *
+   * <p>The two recoverable faults have separate budgets: contention clears on its own and retries
+   * here against {@link #MAX_RETRIES}, while a 421 needs {@code flush} to re-claim, which only the
+   * caller can drive.
+   *
+   * <p>An exhausted budget propagates the last error as itself rather than a synthesized one — "429
+   * after nine tries" beats "checkpoint failed".
+   */
+  private static <T> Attempt<T> issue(Call<T> call) {
+    int retries = 0;
+    while (true) {
+      try {
+        return new Attempt<T>(call.run(), false);
+      } catch (LanceDbRestClient.HttpException e) {
+        if (isLostClaim(e)) {
+          return new Attempt<T>(null, true);
+        }
+        if (!isRetryable(e) || retries >= MAX_RETRIES) {
+          throw e;
+        }
+        backoff(retries);
+        retries++;
+      }
+    }
+  }
+
+  /** {@link #issue} for a call with no return value. Returns true when the claim was lost. */
+  private static boolean issueVoid(Runnable call) {
+    return issue(
+            () -> {
+              call.run();
+              return Boolean.TRUE;
+            })
+        .lostClaim;
+  }
+
+  /** Sleep before re-issuing a retryable request. Doubles up to {@link #RETRY_BACKOFF_MAX_MS}. */
+  private static void backoff(int attempt) {
+    long delay = RETRY_BACKOFF_BASE_MS << Math.min(attempt, 8);
+    sleep(Math.min(delay, RETRY_BACKOFF_MAX_MS));
+  }
+
+  private static void sleep(long millis) {
+    try {
+      Thread.sleep(millis);
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
+      throw new IllegalStateException("Interrupted while waiting on the LSM checkpoint", e);
+    }
+  }
+
+  private String route(String operation) {
+    return "/v1/table/" + tableIdentifier + "/" + operation + "/";
+  }
+
+  /** What one LSM request produced: its value, or word that the owning node holds no claim. */
+  private static final class Attempt<T> {
+    private final T value;
+    private final boolean lostClaim;
+
+    private Attempt(T value, boolean lostClaim) {
+      this.value = value;
+      this.lostClaim = lostClaim;
+    }
+  }
+
+  @FunctionalInterface
+  private interface Call<T> {
+    T run();
+  }
+}

java/lancedb-core/src/main/java/com/lancedb/LsmStats.java

@@ -0,0 +1,56 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Live per-bucket LSM state, as returned by {@link LanceDbTableLsm#getLsmStats()}.
+ *
+ * <p>Nothing here is derived: sums and differences (total L0 bytes, WAL lag) are the caller's to
+ * compute. There is no "LSM is off" shape — that case is an empty {@link java.util.Optional},
+ * because a stats object of zeros would read as measurements.
+ */
+public class LsmStats {
+  private static final String CONTEXT = "lsm stats";
+
+  private final List<BucketStats> buckets;
+
+  LsmStats(List<BucketStats> buckets) {
+    this.buckets = Collections.unmodifiableList(buckets);
+  }
+
+  /** One entry per bucket. */
+  public List<BucketStats> buckets() {
+    return buckets;
+  }
+
+  static LsmStats fromJson(JsonNode node) {
+    JsonFields.requiredObject(node, CONTEXT);
+    List<BucketStats> buckets = new ArrayList<BucketStats>();
+    for (JsonNode bucket : JsonFields.requiredArray(node, "buckets", CONTEXT)) {
+      buckets.add(BucketStats.fromJson(bucket));
+    }
+    return new LsmStats(buckets);
+  }
+
+  @Override
+  public String toString() {
+    return "LsmStats{buckets=" + buckets + "}";
+  }
+}

java/lancedb-core/src/main/java/com/lancedb/LsmWriteSpec.java

@@ -0,0 +1,260 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Specification selecting Lance's MemWAL LSM-style write path for {@code mergeInsert}.
+ *
+ * <p>Construct via {@link #bucket}, {@link #identity}, or {@link #unsharded}, then optionally chain
+ * {@link #withMaintainedIndexes} and {@link #withWriterConfigDefaults}. Install it with {@link
+ * LanceDbTableLsm#setLsmWriteSpec} and remove it with {@link LanceDbTableLsm#unsetLsmWriteSpec}.
+ *
+ * <p>This is deliberately not {@code org.lance.memwal.InitializeMemWalParams}. That type is Lance's
+ * own, and its maintained-index default is the opposite of this one: it defaults to maintaining
+ * <em>nothing</em>, while a fresh spec here maintains <em>every</em> index. It also cannot express
+ * the null that asks the server to resolve the set.
+ */
+public class LsmWriteSpec {
+
+  /** How writes are routed to MemWAL shards. */
+  public enum Sharding {
+    /** Hash-bucket writes by a scalar column. */
+    BUCKET("bucket"),
+    /** Shard by the raw value of a scalar column. */
+    IDENTITY("identity"),
+    /** Route every write to a single shard. */
+    UNSHARDED("unsharded");
+
+    private final String wireName;
+
+    Sharding(String wireName) {
+      this.wireName = wireName;
+    }
+
+    String wireName() {
+      return wireName;
+    }
+
+    static Sharding fromWireName(String name) {
+      for (Sharding s : values()) {
+        if (s.wireName.equals(name)) {
+          return s;
+        }
+      }
+      throw new IllegalArgumentException("Unknown sharding mode: " + name);
+    }
+  }
+
+  private final Sharding sharding;
+  private final String column;
+  private final Integer numBuckets;
+  private final List<String> maintainedIndexes;
+  private final Map<String, String> writerConfigDefaults;
+
+  private LsmWriteSpec(
+      Sharding sharding,
+      String column,
+      Integer numBuckets,
+      List<String> maintainedIndexes,
+      Map<String, String> writerConfigDefaults) {
+    this.sharding = sharding;
+    this.column = column;
+    this.numBuckets = numBuckets;
+    this.maintainedIndexes = maintainedIndexes;
+    this.writerConfigDefaults = writerConfigDefaults;
+  }
+
+  /**
+   * Hash-bucket sharding by a scalar column, maintaining every index on the table.
+   *
+   * <p>Iceberg-compatible Murmur3-x86-32 (seed 0) is used, so each row's {@code bucket(column,
+   * numBuckets)} value is stable across processes.
+   *
+   * @param column A non-nested column with a supported scalar type.
+   * @param numBuckets The number of buckets, in {@code [1, 1024]}.
+   */
+  public static LsmWriteSpec bucket(String column, int numBuckets) {
+    if (column == null || column.trim().isEmpty()) {
+      throw new IllegalArgumentException("Column cannot be null or empty");
+    }
+    return new LsmWriteSpec(
+        Sharding.BUCKET, column, numBuckets, null, new HashMap<String, String>());
+  }
+
+  /**
+   * Identity sharding — shard by the raw value of {@code column} — maintaining every index on the
+   * table.
+   *
+   * <p>{@code column} must be a deterministic function of the unenforced primary key: every row
+   * with a given primary key must always produce the same {@code column} value, or upserts of that
+   * key can land in different shards and a stale version can win.
+   */
+  public static LsmWriteSpec identity(String column) {
+    if (column == null || column.trim().isEmpty()) {
+      throw new IllegalArgumentException("Column cannot be null or empty");
+    }
+    return new LsmWriteSpec(Sharding.IDENTITY, column, null, null, new HashMap<String, String>());
+  }
+
+  /** No sharding — every write goes to a single MemWAL shard — maintaining every index. */
+  public static LsmWriteSpec unsharded() {
+    return new LsmWriteSpec(Sharding.UNSHARDED, null, null, null, new HashMap<String, String>());
+  }
+
+  /**
+   * Set the indexes the MemWAL keeps up to date as rows are appended.
+   *
+   * <p>Pass {@code null} — the default for a fresh spec — to maintain every index the MemWAL can,
+   * resolved when the spec is installed. That is a snapshot: indexes created later are not
+   * maintained until the spec is unset and set again. Pass an empty list to maintain none.
+   *
+   * <p>Note that {@code null} and the empty list mean opposite things here.
+   */
+  public LsmWriteSpec withMaintainedIndexes(List<String> maintainedIndexes) {
+    return new LsmWriteSpec(
+        sharding,
+        column,
+        numBuckets,
+        maintainedIndexes == null ? null : new ArrayList<String>(maintainedIndexes),
+        writerConfigDefaults);
+  }
+
+  /**
+   * Set default {@code ShardWriter} configuration recorded in the MemWAL index.
+   *
+   * <p>A sparse override map — only the keys you set are recorded. Recognized keys include {@code
+   * durable_write}, {@code max_wal_buffer_size}, {@code max_memtable_size}, {@code
+   * max_memtable_rows}, {@code max_memtable_batches}, {@code manifest_scan_batch_size}, {@code
+   * max_unflushed_memtable_bytes}, and {@code enable_memtable}. Duration knobs carry an {@code _ms}
+   * suffix, such as {@code max_wal_flush_interval_ms}.
+   */
+  public LsmWriteSpec withWriterConfigDefaults(Map<String, String> writerConfigDefaults) {
+    if (writerConfigDefaults == null) {
+      throw new IllegalArgumentException("writerConfigDefaults cannot be null");
+    }
+    return new LsmWriteSpec(
+        sharding,
+        column,
+        numBuckets,
+        maintainedIndexes,
+        new HashMap<String, String>(writerConfigDefaults));
+  }
+
+  /** How writes are routed to shards. */
+  public Sharding sharding() {
+    return sharding;
+  }
+
+  /** The sharding column for {@link Sharding#BUCKET} and {@link Sharding#IDENTITY}, else null. */
+  public String column() {
+    return column;
+  }
+
+  /** The bucket count for {@link Sharding#BUCKET}, else null. */
+  public Integer numBuckets() {
+    return numBuckets;
+  }
+
+  /**
+   * The indexes the MemWAL maintains, or null to have the server resolve every maintainable index
+   * on install. An empty list means none.
+   */
+  public List<String> maintainedIndexes() {
+    return maintainedIndexes == null ? null : Collections.unmodifiableList(maintainedIndexes);
+  }
+
+  /** Default {@code ShardWriter} configuration recorded in the MemWAL index. */
+  public Map<String, String> writerConfigDefaults() {
+    return Collections.unmodifiableMap(writerConfigDefaults);
+  }
+
+  /** Render this spec as the {@code set_lsm_write_spec} request body. */
+  Map<String, Object> toRequestBody() {
+    Map<String, Object> shardingBody = new LinkedHashMap<String, Object>();
+    shardingBody.put("mode", sharding.wireName());
+    if (column != null) {
+      shardingBody.put("column", column);
+    }
+    if (numBuckets != null) {
+      shardingBody.put("num_buckets", numBuckets);
+    }
+
+    Map<String, Object> body = new LinkedHashMap<String, Object>();
+    body.put("sharding", shardingBody);
+    // Null is meaningful: it asks the server to resolve every maintainable index.
+    body.put("maintained_indexes", maintainedIndexes);
+    body.put("writer_config_defaults", writerConfigDefaults);
+    return body;
+  }
+
+  /**
+   * Rebuild a spec from a {@code get_lsm_write_spec} response body.
+   *
+   * <p>The server always reports a concrete maintained-index list, so a null selection never
+   * round-trips.
+   */
+  static LsmWriteSpec fromJson(JsonNode node) {
+    JsonNode shardingNode = node.get("sharding");
+    if (shardingNode == null || shardingNode.get("mode") == null) {
+      throw new IllegalStateException("get_lsm_write_spec response has no sharding mode");
+    }
+    Sharding sharding = Sharding.fromWireName(shardingNode.get("mode").asText());
+
+    String column = shardingNode.hasNonNull("column") ? shardingNode.get("column").asText() : null;
+    Integer numBuckets =
+        shardingNode.hasNonNull("num_buckets") ? shardingNode.get("num_buckets").asInt() : null;
+
+    List<String> maintainedIndexes = new ArrayList<String>();
+    JsonNode indexesNode = node.get("maintained_indexes");
+    if (indexesNode != null && indexesNode.isArray()) {
+      for (JsonNode index : indexesNode) {
+        maintainedIndexes.add(index.asText());
+      }
+    }
+
+    Map<String, String> defaults = new HashMap<String, String>();
+    JsonNode defaultsNode = node.get("writer_config_defaults");
+    if (defaultsNode != null && defaultsNode.isObject()) {
+      defaultsNode
+          .fieldNames()
+          .forEachRemaining(name -> defaults.put(name, defaultsNode.get(name).asText()));
+    }
+
+    return new LsmWriteSpec(sharding, column, numBuckets, maintainedIndexes, defaults);
+  }
+
+  @Override
+  public String toString() {
+    return "LsmWriteSpec{sharding="
+        + sharding
+        + ", column="
+        + column
+        + ", numBuckets="
+        + numBuckets
+        + ", maintainedIndexes="
+        + maintainedIndexes
+        + ", writerConfigDefaults="
+        + writerConfigDefaults
+        + "}";
+  }
+}

java/lancedb-core/src/main/java/com/lancedb/MemtableStats.java

@@ -0,0 +1,99 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/** One in-memory memtable. */
+public class MemtableStats {
+  private static final String CONTEXT = "memtable stats";
+
+  private final long generation;
+  private final long rows;
+  private final long bytes;
+  private final long batches;
+  private final List<String> indexes;
+
+  MemtableStats(long generation, long rows, long bytes, long batches, List<String> indexes) {
+    this.generation = generation;
+    this.rows = rows;
+    this.bytes = bytes;
+    this.batches = batches;
+    this.indexes = Collections.unmodifiableList(indexes);
+  }
+
+  /** The generation this memtable will become once sealed. */
+  public long generation() {
+    return generation;
+  }
+
+  /** Rows currently buffered. */
+  public long rows() {
+    return rows;
+  }
+
+  /** Estimated in-memory size. */
+  public long bytes() {
+    return bytes;
+  }
+
+  /** Record batches currently buffered. */
+  public long batches() {
+    return batches;
+  }
+
+  /**
+   * Names of the indexes this memtable carries. An absent name is the whole answer to "why is my
+   * fresh-tier search on that column brute-force".
+   */
+  public List<String> indexes() {
+    return indexes;
+  }
+
+  static MemtableStats fromJson(JsonNode node) {
+    JsonFields.requiredObject(node, CONTEXT);
+    List<String> indexes = new ArrayList<String>();
+    for (JsonNode index : JsonFields.requiredArray(node, "indexes", CONTEXT)) {
+      if (!index.isTextual()) {
+        throw new IllegalStateException(CONTEXT + " has a non-string index name: " + index);
+      }
+      indexes.add(index.asText());
+    }
+    return new MemtableStats(
+        JsonFields.requiredLong(node, "generation", CONTEXT),
+        JsonFields.requiredLong(node, "rows", CONTEXT),
+        JsonFields.requiredLong(node, "bytes", CONTEXT),
+        JsonFields.requiredLong(node, "batches", CONTEXT),
+        indexes);
+  }
+
+  @Override
+  public String toString() {
+    return "MemtableStats{generation="
+        + generation
+        + ", rows="
+        + rows
+        + ", bytes="
+        + bytes
+        + ", batches="
+        + batches
+        + ", indexes="
+        + indexes
+        + "}";
+  }
+}

java/lancedb-core/src/test/java/com/lancedb/LanceDbTableLsmTest.java

@@ -0,0 +1,570 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.lancedb;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.sun.net.httpserver.HttpServer;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Deque;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Unit tests for the MemWAL LSM routes, run against a scripted local HTTP server.
+ *
+ * <p>The wire assertions mirror the Rust mocked-endpoint tests in {@code
+ * rust/lancedb/src/remote/table.rs}, which are the contract these routes have to match.
+ */
+public class LanceDbTableLsmTest {
+  private static final ObjectMapper MAPPER = new ObjectMapper();
+
+  private HttpServer server;
+  private LanceDbRestClient client;
+  private LanceDbTableLsm lsm;
+
+  private final List<String> requestPaths = Collections.synchronizedList(new ArrayList<String>());
+  private final List<String> requestBodies = Collections.synchronizedList(new ArrayList<String>());
+  private final Map<String, Deque<Reply>> replies = new ConcurrentHashMap<String, Deque<Reply>>();
+
+  @BeforeEach
+  public void setUp() throws IOException {
+    start();
+  }
+
+  /** Tear down and restart the scripted server, for a test that scripts several exchanges. */
+  private void setUpFresh() {
+    try {
+      client.close();
+      server.stop(0);
+      requestPaths.clear();
+      requestBodies.clear();
+      replies.clear();
+      start();
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+
+  private void start() throws IOException {
+    server = HttpServer.create(new InetSocketAddress("127.0.0.1", 0), 0);
+    server.createContext(
+        "/",
+        exchange -> {
+          String path = exchange.getRequestURI().getPath();
+          requestPaths.add(path);
+          requestBodies.add(readAll(exchange.getRequestBody()));
+
+          Reply reply = nextReply(path);
+          byte[] out = reply.body.getBytes(StandardCharsets.UTF_8);
+          exchange.sendResponseHeaders(reply.status, out.length == 0 ? -1 : out.length);
+          if (out.length > 0) {
+            exchange.getResponseBody().write(out);
+          }
+          exchange.close();
+        });
+    server.start();
+
+    client =
+        LanceDbNamespaceClientBuilder.newBuilder()
+            .apiKey("test-key")
+            .database("test-db")
+            .endpoint("http://127.0.0.1:" + server.getAddress().getPort())
+            .buildRestClient();
+    lsm = new LanceDbTableLsm(client, "my_table");
+  }
+
+  @AfterEach
+  public void tearDown() throws IOException {
+    client.close();
+    server.stop(0);
+  }
+
+  // ===========================================================================
+  // set / unset / get spec
+  // ===========================================================================
+
+  @Test
+  public void testSetLsmWriteSpecUnsharded() throws Exception {
+    enqueue("set_lsm_write_spec", 200, "");
+
+    lsm.setLsmWriteSpec(LsmWriteSpec.unsharded());
+
+    assertEquals("/v1/table/my_table/set_lsm_write_spec/", requestPaths.get(0));
+    JsonNode body = MAPPER.readTree(requestBodies.get(0));
+    assertEquals("unsharded", body.get("sharding").get("mode").asText());
+    assertFalse(body.get("sharding").has("column"));
+    assertFalse(body.get("sharding").has("num_buckets"));
+  }
+
+  @Test
+  public void testSetLsmWriteSpecBucket() throws Exception {
+    enqueue("set_lsm_write_spec", 200, "");
+
+    lsm.setLsmWriteSpec(
+        LsmWriteSpec.bucket("id", 16).withMaintainedIndexes(Arrays.asList("id_idx")));
+
+    JsonNode body = MAPPER.readTree(requestBodies.get(0));
+    assertEquals("bucket", body.get("sharding").get("mode").asText());
+    assertEquals("id", body.get("sharding").get("column").asText());
+    assertEquals(16, body.get("sharding").get("num_buckets").asInt());
+    assertEquals(1, body.get("maintained_indexes").size());
+    assertEquals("id_idx", body.get("maintained_indexes").get(0).asText());
+  }
+
+  @Test
+  public void testSetLsmWriteSpecIdentity() throws Exception {
+    enqueue("set_lsm_write_spec", 200, "");
+
+    lsm.setLsmWriteSpec(LsmWriteSpec.identity("tenant"));
+
+    JsonNode body = MAPPER.readTree(requestBodies.get(0));
+    assertEquals("identity", body.get("sharding").get("mode").asText());
+    assertEquals("tenant", body.get("sharding").get("column").asText());
+    assertFalse(body.get("sharding").has("num_buckets"));
+  }
+
+  /**
+   * The tri-state that motivated a LanceDB-owned spec type: a null selection asks the server to
+   * resolve every maintainable index, while an empty list asks for none. They must not collapse.
+   */
+  @Test
+  public void testMaintainedIndexesNullAndEmptyAreDistinctOnTheWire() throws Exception {
+    enqueue("set_lsm_write_spec", 200, "");
+
+    lsm.setLsmWriteSpec(LsmWriteSpec.unsharded());
+    JsonNode fresh = MAPPER.readTree(requestBodies.get(0));
+    assertTrue(fresh.has("maintained_indexes"), "the key must be present");
+    assertTrue(fresh.get("maintained_indexes").isNull(), "a fresh spec sends null, not []");
+
+    lsm.setLsmWriteSpec(
+        LsmWriteSpec.unsharded().withMaintainedIndexes(Collections.<String>emptyList()));
+    JsonNode none = MAPPER.readTree(requestBodies.get(1));
+    assertTrue(none.get("maintained_indexes").isArray());
+    assertEquals(0, none.get("maintained_indexes").size());
+  }
+
+  @Test
+  public void testSetLsmWriteSpecWriterConfigDefaults() throws Exception {
+    enqueue("set_lsm_write_spec", 200, "");
+
+    Map<String, String> defaults = new HashMap<String, String>();
+    defaults.put("max_memtable_rows", "50000");
+    lsm.setLsmWriteSpec(LsmWriteSpec.unsharded().withWriterConfigDefaults(defaults));
+
+    JsonNode body = MAPPER.readTree(requestBodies.get(0));
+    assertEquals("50000", body.get("writer_config_defaults").get("max_memtable_rows").asText());
+  }
+
+  @Test
+  public void testUnsetLsmWriteSpec() {
+    enqueue("unset_lsm_write_spec", 200, "");
+
+    lsm.unsetLsmWriteSpec();
+
+    assertEquals("/v1/table/my_table/unset_lsm_write_spec/", requestPaths.get(0));
+    assertEquals("", requestBodies.get(0));
+  }
+
+  @Test
+  public void testGetLsmWriteSpec() {
+    enqueue(
+        "get_lsm_write_spec",
+        200,
+        "{\"lsm_write_spec\":{\"sharding\":{\"mode\":\"bucket\",\"column\":\"id\","
+            + "\"num_buckets\":16},\"maintained_indexes\":[\"id_idx\"],"
+            + "\"writer_config_defaults\":{\"durable_write\":\"true\"}}}");
+
+    Optional<LsmWriteSpec> spec = lsm.getLsmWriteSpec();
+
+    assertTrue(spec.isPresent());
+    assertEquals(LsmWriteSpec.Sharding.BUCKET, spec.get().sharding());
+    assertEquals("id", spec.get().column());
+    assertEquals(Integer.valueOf(16), spec.get().numBuckets());
+    assertEquals(Arrays.asList("id_idx"), spec.get().maintainedIndexes());
+    assertEquals("true", spec.get().writerConfigDefaults().get("durable_write"));
+  }
+
+  @Test
+  public void testGetLsmWriteSpecAbsent() {
+    enqueue("get_lsm_write_spec", 200, "{\"lsm_write_spec\":null}");
+
+    assertFalse(lsm.getLsmWriteSpec().isPresent());
+  }
+
+  // ===========================================================================
+  // stats
+  // ===========================================================================
+
+  @Test
+  public void testGetLsmStats() throws Exception {
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false, 7L, 8L)));
+
+    Optional<LsmStats> got = lsm.getLsmStats(true);
+
+    assertEquals("/v1/table/my_table/get_lsm_stats/", requestPaths.get(0));
+    assertTrue(MAPPER.readTree(requestBodies.get(0)).get("include_generation_rows").asBoolean());
+    assertTrue(got.isPresent());
+    BucketStats decoded = got.get().buckets().get(0);
+    assertEquals("shard-0", decoded.shardId());
+    assertEquals("Active", decoded.status());
+    assertEquals(1, decoded.writerEpoch());
+    assertEquals(2, decoded.manifestVersion());
+    assertEquals(9, decoded.currentGeneration());
+    assertFalse(decoded.compacting());
+    assertEquals(Arrays.asList(7L, 8L), generationNumbers(decoded));
+    assertEquals(1024, decoded.generations().get(0).bytes());
+    assertFalse(decoded.generations().get(0).rows().isPresent(), "rows absent unless requested");
+    assertFalse(decoded.memtables().isPresent(), "absent memtables stay absent");
+  }
+
+  /** The optional fields decode when the server does send them. */
+  @Test
+  public void testGetLsmStatsDecodesOptionalFields() {
+    enqueue(
+        "get_lsm_stats",
+        200,
+        "{\"lsm_stats\":{\"buckets\":[{\"shard_id\":\"shard-0\",\"status\":\"Active\","
+            + "\"writer_epoch\":1,\"manifest_version\":2,\"current_generation\":9,"
+            + "\"replay_after_wal_entry_position\":3,\"wal_entry_position_last_seen\":11,"
+            + "\"generations\":[{\"generation\":7,\"bytes\":1024,\"rows\":42}],"
+            + "\"compacting\":true,\"memtables\":[{\"generation\":8,\"rows\":5,"
+            + "\"bytes\":64,\"batches\":2,\"indexes\":[\"id_idx\"]}]}]}}");
+
+    BucketStats decoded = lsm.getLsmStats(true).get().buckets().get(0);
+
+    assertEquals(3, decoded.replayAfterWalEntryPosition());
+    assertEquals(11, decoded.walEntryPositionLastSeen());
+    assertTrue(decoded.compacting());
+    assertEquals(42, decoded.generations().get(0).rows().getAsLong());
+    assertTrue(decoded.memtables().isPresent());
+    MemtableStats memtable = decoded.memtables().get().get(0);
+    assertEquals(8, memtable.generation());
+    assertEquals(5, memtable.rows());
+    assertEquals(64, memtable.bytes());
+    assertEquals(2, memtable.batches());
+    assertEquals(Arrays.asList("id_idx"), memtable.indexes());
+  }
+
+  @Test
+  public void testGetLsmStatsAbsentWhenLsmDisabled() {
+    enqueue("get_lsm_stats", 200, "{\"lsm_stats\":null}");
+
+    assertFalse(lsm.getLsmStats().isPresent());
+  }
+
+  @Test
+  public void testGetLsmStatsDefaultsToExcludingGenerationRows() throws Exception {
+    enqueue("get_lsm_stats", 200, stats());
+
+    lsm.getLsmStats();
+
+    assertFalse(MAPPER.readTree(requestBodies.get(0)).get("include_generation_rows").asBoolean());
+  }
+
+  // ===========================================================================
+  // flush / compact
+  // ===========================================================================
+
+  @Test
+  public void testFlushAndCompactRoutes() {
+    enqueue("flush_lsm", 200, "");
+    enqueue("compact_lsm", 200, "");
+
+    lsm.flushLsm();
+    lsm.compactLsm();
+
+    assertEquals("/v1/table/my_table/flush_lsm/", requestPaths.get(0));
+    assertEquals("/v1/table/my_table/compact_lsm/", requestPaths.get(1));
+  }
+
+  @Test
+  public void testHttpErrorCarriesStatus() {
+    enqueue("flush_lsm", 404, "no such table");
+
+    LanceDbRestClient.HttpException e =
+        assertThrows(LanceDbRestClient.HttpException.class, () -> lsm.flushLsm());
+    assertEquals(404, e.statusCode());
+  }
+
+  // ===========================================================================
+  // checkpoint
+  // ===========================================================================
+
+  @Test
+  public void testCheckpointReturnsWhenLsmDisabled() {
+    enqueue("flush_lsm", 200, "");
+    enqueue("get_lsm_stats", 200, "{\"lsm_stats\":null}");
+
+    lsm.checkpointLsm();
+
+    assertEquals(0, countCalls("compact_lsm"), "nothing to compact when the LSM path is off");
+  }
+
+  @Test
+  public void testCheckpointReturnsWhenNoGenerationsOutstanding() {
+    enqueue("flush_lsm", 200, "");
+    // A bucket with no L0 generations yields no target, so the drain never starts.
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false)));
+
+    lsm.checkpointLsm();
+
+    assertEquals(0, countCalls("compact_lsm"));
+  }
+
+  @Test
+  public void testCheckpointConvergesOnceTargetGenerationsAreGone() {
+    enqueue("flush_lsm", 200, "");
+    // Watermark read: shard-0 holds generations 7 and 8, so target = 8.
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false, 7L, 8L)));
+    // First drain poll: both still outstanding, nothing compacting -> dispatch a pass.
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false, 7L, 8L)));
+    // Second drain poll: drained past the target -> done.
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false, 9L)));
+    enqueue("compact_lsm", 200, "");
+
+    lsm.checkpointLsm();
+
+    assertEquals(1, countCalls("compact_lsm"), "one pass dispatched");
+    assertEquals(3, countCalls("get_lsm_stats"), "watermark read plus two drain polls");
+  }
+
+  @Test
+  public void testCheckpointDoesNotPileOnWhileEveryTargetBucketIsCompacting() {
+    enqueue("flush_lsm", 200, "");
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", true, 4L)));
+    // Still compacting on the first poll, so no pass is dispatched; then it drains.
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", true, 4L)));
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false, 5L)));
+
+    lsm.checkpointLsm();
+
+    assertEquals(0, countCalls("compact_lsm"), "a latched bucket is left alone");
+  }
+
+  @Test
+  public void testCheckpointRetriesFromFlushAfterLostClaim() {
+    // 421 on the watermark read: the node lost its claim, so the whole thing restarts
+    // from flush rather than retrying the read in place.
+    enqueue("flush_lsm", 200, "");
+    enqueue("get_lsm_stats", 421, "no claim");
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false)));
+
+    lsm.checkpointLsm();
+
+    assertEquals(2, countCalls("flush_lsm"), "re-issued from flush");
+  }
+
+  @Test
+  public void testCheckpointRetriesRetryableStatusInPlace() {
+    enqueue("flush_lsm", 429, "latch held");
+    enqueue("flush_lsm", 200, "");
+    enqueue("get_lsm_stats", 200, stats(bucket("shard-0", false)));
+
+    lsm.checkpointLsm();
+
+    assertEquals(2, countCalls("flush_lsm"), "429 retried in place, not re-issued");
+  }
+
+  @Test
+  public void testCheckpointPropagatesTerminalStatus() {
+    enqueue("flush_lsm", 400, "bad request");
+
+    LanceDbRestClient.HttpException e =
+        assertThrows(LanceDbRestClient.HttpException.class, () -> lsm.checkpointLsm());
+    assertEquals(400, e.statusCode());
+    assertEquals(1, countCalls("flush_lsm"), "a terminal status is not retried");
+  }
+
+  @Test
+  public void testCheckpointGivesUpAfterRepeatedLostClaims() {
+    enqueue("flush_lsm", 421, "no claim");
+
+    IllegalStateException e = assertThrows(IllegalStateException.class, () -> lsm.checkpointLsm());
+    assertTrue(e.getMessage().contains("kept losing its claim"), e.getMessage());
+    assertEquals(4, countCalls("flush_lsm"), "the initial attempt plus MAX_REISSUES");
+  }
+
+  // ===========================================================================
+  // strict decoding
+  // ===========================================================================
+
+  /**
+   * A stats payload that does not decode must fail closed. Every one of these bodies used to be
+   * read as "no buckets", which is indistinguishable from a drained table, so {@code checkpointLsm}
+   * reported convergence for a checkpoint that never ran.
+   */
+  @Test
+  public void testCheckpointRejectsMalformedStats() {
+    Map<String, String> malformed = new LinkedHashMap<String, String>();
+    malformed.put("no response body at all", "");
+    malformed.put("stats object with no buckets", "{\"lsm_stats\":{}}");
+    malformed.put("bucket missing its required fields", "{\"lsm_stats\":{\"buckets\":[{}]}}");
+    malformed.put(
+        "bucket missing generations",
+        "{\"lsm_stats\":{\"buckets\":[{\"shard_id\":\"shard-0\",\"status\":\"Active\","
+            + "\"writer_epoch\":1,\"manifest_version\":2,\"current_generation\":9,"
+            + "\"replay_after_wal_entry_position\":0,\"wal_entry_position_last_seen\":0,"
+            + "\"compacting\":false}]}}");
+    malformed.put(
+        "generation with a non-numeric generation number",
+        "{\"lsm_stats\":{\"buckets\":[{\"shard_id\":\"shard-0\",\"status\":\"Active\","
+            + "\"writer_epoch\":1,\"manifest_version\":2,\"current_generation\":9,"
+            + "\"replay_after_wal_entry_position\":0,\"wal_entry_position_last_seen\":0,"
+            + "\"generations\":[{\"generation\":\"7\",\"bytes\":1024}],"
+            + "\"compacting\":false}]}}");
+
+    for (Map.Entry<String, String> each : malformed.entrySet()) {
+      setUpFresh();
+      enqueue("flush_lsm", 200, "");
+      enqueue("get_lsm_stats", 200, each.getValue());
+
+      assertThrows(
+          IllegalStateException.class,
+          () -> lsm.checkpointLsm(),
+          each.getKey() + " must not report convergence");
+    }
+  }
+
+  /** The one shape that legitimately means "this table has no LSM write path". */
+  @Test
+  public void testCheckpointTreatsNullStatsAsNotWalBacked() {
+    enqueue("flush_lsm", 200, "");
+    enqueue("get_lsm_stats", 200, "{\"lsm_stats\":null}");
+
+    lsm.checkpointLsm();
+
+    assertEquals(1, countCalls("get_lsm_stats"));
+  }
+
+  // ===========================================================================
+  // retry budget
+  // ===========================================================================
+
+  /**
+   * The transport must not retry on the checkpoint loop's behalf. Apache HttpClient's default
+   * strategy retries exactly 429 and 503 — the two statuses {@code isRetryable} owns — which
+   * doubled every budget here and also retried {@code compact_lsm} in place, where the loop is
+   * built to fall through to a fresh stats poll instead.
+   */
+  @Test
+  public void testCheckpointRetryBudgetIsNotDoubledByTheTransport() {
+    enqueue("flush_lsm", 429, "latch held");
+
+    LanceDbRestClient.HttpException e =
+        assertThrows(LanceDbRestClient.HttpException.class, () -> lsm.checkpointLsm());
+
+    assertEquals(429, e.statusCode(), "the exhausted budget propagates the last error as itself");
+    assertEquals(9, countCalls("flush_lsm"), "the initial request plus MAX_RETRIES, and no more");
+  }
+
+  // ===========================================================================
+  // harness
+  // ===========================================================================
+
+  private static List<Long> generationNumbers(BucketStats bucket) {
+    List<Long> numbers = new ArrayList<Long>();
+    for (GenerationStats generation : bucket.generations()) {
+      numbers.add(generation.generation());
+    }
+    return numbers;
+  }
+
+  /** Build an {@code lsm_stats} response body from bucket fragments. */
+  private static String stats(String... buckets) {
+    return "{\"lsm_stats\":{\"buckets\":[" + String.join(",", buckets) + "]}}";
+  }
+
+  private static String bucket(String shardId, boolean compacting, Long... generations) {
+    StringBuilder gens = new StringBuilder();
+    for (Long generation : generations) {
+      if (gens.length() > 0) {
+        gens.append(",");
+      }
+      gens.append("{\"generation\":").append(generation).append(",\"bytes\":1024}");
+    }
+    return "{\"shard_id\":\""
+        + shardId
+        + "\",\"status\":\"Active\",\"writer_epoch\":1,\"manifest_version\":2,"
+        + "\"current_generation\":9,\"replay_after_wal_entry_position\":0,"
+        + "\"wal_entry_position_last_seen\":0,\"generations\":["
+        + gens
+        + "],\"compacting\":"
+        + compacting
+        + "}";
+  }
+
+  /** Queue a reply for an operation. The last queued reply repeats once the queue drains. */
+  private void enqueue(String operation, int status, String body) {
+    replies.computeIfAbsent(operation, key -> new ArrayDeque<Reply>()).add(new Reply(status, body));
+  }
+
+  private Reply nextReply(String path) {
+    String operation = operationOf(path);
+    Deque<Reply> queued = replies.get(operation);
+    if (queued == null || queued.isEmpty()) {
+      return new Reply(200, "");
+    }
+    return queued.size() > 1 ? queued.poll() : queued.peek();
+  }
+
+  private long countCalls(String operation) {
+    return requestPaths.stream().filter(path -> operationOf(path).equals(operation)).count();
+  }
+
+  /** {@code /v1/table/my_table/flush_lsm/} -> {@code flush_lsm}. */
+  private static String operationOf(String path) {
+    String[] segments = path.split("/");
+    return segments.length == 0 ? "" : segments[segments.length - 1];
+  }
+
+  private static String readAll(InputStream in) throws IOException {
+    ByteArrayOutputStream out = new ByteArrayOutputStream();
+    byte[] buffer = new byte[4096];
+    int read;
+    while ((read = in.read(buffer)) != -1) {
+      out.write(buffer, 0, read);
+    }
+    return new String(out.toByteArray(), StandardCharsets.UTF_8);
+  }
+
+  private static final class Reply {
+    private final int status;
+    private final String body;
+
+    private Reply(int status, String body) {
+      this.status = status;
+      this.body = body;
+    }
+  }
+}

java/pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.lancedb</groupId>
     <artifactId>lancedb-parent</artifactId>
-    <version>0.37.1-beta.0</version>
+    <version>0.38.0-beta.3</version>
     <packaging>pom</packaging>
     <name>${project.artifactId}</name>
     <description>LanceDB Java SDK Parent POM</description>
@@ -28,7 +28,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <arrow.version>15.0.0</arrow.version>
-        <lance-core.version>10.1.0-beta.1</lance-core.version>
+        <lance-core.version>11.0.0-beta.18</lance-core.version>
         <spotless.skip>false</spotless.skip>
         <spotless.version>2.30.0</spotless.version>
         <spotless.java.googlejavaformat.version>1.7</spotless.java.googlejavaformat.version>

nodejs/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "lancedb-nodejs"
 edition.workspace = true
-version = "0.37.1-beta.0"
+version = "0.38.0-beta.3"
 publish = false
 license.workspace = true
 description.workspace = true
@@ -16,12 +16,12 @@ crate-type = ["cdylib"]
 async-trait.workspace = true
 arrow-ipc.workspace = true
 arrow-array.workspace = true
-arrow-buffer = "58.0.0"
+arrow-buffer.workspace = true
 half.workspace = true
 arrow-schema.workspace = true
 env_logger.workspace = true
 futures.workspace = true
-lancedb = { path = "../rust/lancedb", default-features = false }
+lancedb.workspace = true
 lance-namespace.workspace = true
 napi = { version = "3.8.3", default-features = false, features = [
     "napi9",
@@ -29,8 +29,8 @@ napi = { version = "3.8.3", default-features = false, features = [
     "chrono_date",
     "serde-json",
 ] }
-chrono = { version = "0.4", default-features = false, features = ["clock"] }
-serde_json = "1"
+chrono.workspace = true
+serde_json.workspace = true
 napi-derive = "3.5.2"
 # Prevent dynamic linking of lzma, which comes from datafusion
 lzma-sys = { version = "0.1", features = ["static"] }

nodejs/__test__/arrow.test.ts

@@ -6,7 +6,9 @@ import * as arrow17 from "apache-arrow-17";
 import * as arrow18 from "apache-arrow-18";
 
 import {
+  Vector as CurrentVector,
   convertToTable,
+  tableFromIPC as currentTableFromIPC,
   fromBufferToRecordBatch,
   fromDataToBuffer,
   fromRecordBatchToBuffer,
@@ -19,6 +21,7 @@ import {
   FunctionOptions,
 } from "../lancedb/embedding/embedding_function";
 import { EmbeddingFunctionConfig } from "../lancedb/embedding/registry";
+import { sanitizeTable } from "../lancedb/sanitize";
 
 // biome-ignore lint/suspicious/noExplicitAny: skip
 function sampleRecords(): Array<Record<string, any>> {
@@ -64,7 +67,11 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
       tableFromIPC,
       DataType,
       Dictionary,
+      RecordBatch: ArrowRecordBatch,
+      Table: ArrowTable,
       Uint8: ArrowUint8,
+      makeData: arrowMakeData,
+      vectorFromArray,
       // biome-ignore lint/suspicious/noExplicitAny: <explanation>
     } = <any>arrow;
     type Schema = ApacheArrow["Schema"];
@@ -166,6 +173,36 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
     }
 
     describe("The function makeArrowTable", function () {
+      it("accepts snake_case embedding metadata like camelCase", function () {
+        const spellings = [
+          // biome-ignore lint/style/useNamingConvention: the Python wire spelling
+          { source_column: "text", vector_column: "vector" },
+          { sourceColumn: "text", vectorColumn: "vector" },
+        ];
+        for (const columns of spellings) {
+          const schema = new Schema(
+            [
+              new Field("text", new Utf8(), false),
+              new Field(
+                "vector",
+                new FixedSizeList(3, new Field("item", new Float32(), true)),
+                false,
+              ),
+            ],
+            new Map([
+              [
+                "embedding_functions",
+                JSON.stringify([{ name: "mock", model: {}, ...columns }]),
+              ],
+            ]),
+          );
+          // The vector field is non-nullable and absent from the data; only a
+          // recognized embedding config makes that acceptable.
+          const table = makeArrowTable([{ text: "hello" }], { schema });
+          expect(table.numRows).toBe(1);
+        }
+      });
+
       it("will use data types from a provided schema instead of inference", async function () {
         const schema = new Schema([
           new Field("a", new Int32(), false),
@@ -197,6 +234,35 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
         expect(table.getChild("d")?.toJSON()).toEqual([9n, 10n, null]);
       });
 
+      it("will use a provided FixedSizeList schema with typed array values", function () {
+        const schema = new Schema([
+          new Field("text", new Utf8(), false),
+          new Field(
+            "vector",
+            new FixedSizeList(3, new Field("item", new Float32(), false)),
+            false,
+          ),
+        ]);
+
+        const table = makeArrowTable(
+          [
+            {
+              text: "foo",
+              vector: new Float32Array([1, 2, 3]),
+            },
+          ],
+          { schema },
+        );
+
+        expect(table.getChild("text")?.toJSON()).toEqual(["foo"]);
+        expect(
+          table
+            .getChild("vector")
+            ?.toJSON()
+            .map((value) => value.toJSON()),
+        ).toEqual([[1, 2, 3]]);
+      });
+
       it("will assume the column `vector` is FixedSizeList<Float32> by default", async function () {
         const schema = new Schema([
           new Field("a", new Float(Precision.DOUBLE), true),
@@ -1025,6 +1091,114 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
     });
 
     describe("when using two versions of arrow", function () {
+      it("preserves a dictionary shared by multiple fields", async function () {
+        const values = ["alpha", "beta", "alpha"];
+        const dictionaryVector = vectorFromArray(values);
+        const batch = new ArrowRecordBatch({
+          first: dictionaryVector.data[0],
+          second: dictionaryVector.data[0],
+        });
+        const table = new ArrowTable([batch]);
+
+        const sanitized = sanitizeTable(table);
+        expect([...sanitized.getChild("first")!]).toEqual(values);
+        expect([...sanitized.getChild("second")!]).toEqual(values);
+        const firstType = sanitized.schema.fields[0].type as {
+          dictionary: unknown;
+        };
+        const secondType = sanitized.schema.fields[1].type as {
+          dictionary: unknown;
+        };
+        expect(secondType.dictionary).toBe(firstType.dictionary);
+        expect(sanitized.batches[0].data.children[1].dictionary).toBe(
+          sanitized.batches[0].data.children[0].dictionary,
+        );
+
+        const buf = await fromDataToBuffer(table);
+        const actual = currentTableFromIPC(buf);
+        expect([...actual.getChild("first")!]).toEqual(values);
+        expect([...actual.getChild("second")!]).toEqual(values);
+      });
+
+      it("preserves shared dictionary data from another Arrow version", async function () {
+        const values = ["alpha", "beta", "alpha"];
+        const dictionaryVector = vectorFromArray(values);
+        const firstBatch = new ArrowRecordBatch({
+          label: dictionaryVector.slice(0, 2).data[0],
+        });
+        const secondBatch = new ArrowRecordBatch({
+          label: dictionaryVector.slice(2).data[0],
+        });
+        const table = new ArrowTable([firstBatch, secondBatch]);
+
+        const sanitized = sanitizeTable(table);
+        expect([...sanitized.getChild("label")!]).toEqual(values);
+
+        const dictionaries = sanitized.batches.map(
+          (batch) => batch.data.children[0].dictionary,
+        );
+        expect(dictionaries[0]).toBeInstanceOf(CurrentVector);
+        expect(dictionaries[1]).toBe(dictionaries[0]);
+
+        const buf = await fromDataToBuffer(table);
+        const actual = currentTableFromIPC(buf);
+        expect([...actual.getChild("label")!]).toEqual(values);
+      });
+
+      it("preserves shared chunks in growing dictionaries", async function () {
+        const type = new Dictionary(new Utf8(), new Int32(), 42, false);
+        const firstDictionary = vectorFromArray(["alpha", "beta"], new Utf8());
+        const secondDictionary = firstDictionary.concat(
+          vectorFromArray(["gamma"], new Utf8()),
+        );
+        const firstData = arrowMakeData({
+          type,
+          data: Int32Array.from([0, 1]),
+          dictionary: firstDictionary,
+        });
+        const secondData = arrowMakeData({
+          type,
+          data: Int32Array.from([2]),
+          dictionary: secondDictionary,
+        });
+        const table = new ArrowTable([
+          new ArrowRecordBatch({ label: firstData }),
+          new ArrowRecordBatch({ label: secondData }),
+        ]);
+
+        const sanitized = sanitizeTable(table);
+        const expected = ["alpha", "beta", "gamma"];
+        expect([...sanitized.getChild("label")!]).toEqual(expected);
+        const firstLocalDictionary =
+          sanitized.batches[0].data.children[0].dictionary!;
+        const secondLocalDictionary =
+          sanitized.batches[1].data.children[0].dictionary!;
+        expect(secondLocalDictionary.data[0]).toBe(
+          firstLocalDictionary.data[0],
+        );
+
+        const buf = await fromTableToBuffer(sanitized);
+        const actual = currentTableFromIPC(buf);
+        expect([...actual.getChild("label")!]).toEqual(expected);
+      });
+
+      it("can serialize list data from another Arrow version", async function () {
+        const values = [["anime", "action"], [], null];
+        const vector = vectorFromArray(
+          values,
+          new List(new Field("item", new Utf8(), true)),
+        );
+        const table = new ArrowTable({ tags: vector });
+
+        const buf = await fromDataToBuffer(table);
+        const actual = currentTableFromIPC(buf);
+        const actualTags = actual.getChild("tags");
+
+        expect(actualTags?.get(0)?.toJSON()).toEqual(values[0]);
+        expect(actualTags?.get(1)?.toJSON()).toEqual(values[1]);
+        expect(actualTags?.get(2)).toBeNull();
+      });
+
       it("can still import data", async function () {
         const schema = new arrow15.Schema([
           new arrow15.Field("id", new arrow15.Int32()),

nodejs/__test__/connection.test.ts

@@ -89,6 +89,16 @@ describe("given a connection", () => {
     await db.createTable("test4", [{ id: 1 }, { id: 2 }]);
   });
 
+  it("should return a completed job when dropping a local table", async () => {
+    await db.createTable("async-drop", [{ id: 1 }]);
+
+    const job = await db.dropTableAsync("async-drop");
+    expect(job.id).toBeNull();
+    await expect(job.status()).resolves.toBe("finished");
+    await job.wait();
+    await expect(db.tableNames()).resolves.toEqual([]);
+  });
+
   it("should fail if creating table twice, unless overwrite is true", async () => {
     let tbl = await db.createTable("test", [{ id: 1 }, { id: 2 }]);
     await expect(tbl.countRows()).resolves.toBe(2);

nodejs/__test__/embedding.test.ts

@@ -11,8 +11,11 @@ import {
   Float16,
   Float32,
   Float64,
+  Int32,
   Schema,
   Utf8,
+  fromDataToBuffer,
+  tableFromIPC,
 } from "../lancedb/arrow";
 import { EmbeddingFunction, LanceSchema } from "../lancedb/embedding";
 import { getRegistry, register } from "../lancedb/embedding/registry";
@@ -184,6 +187,63 @@ describe("embedding functions", () => {
     const vector0 = JSON.parse(JSON.stringify(arr[0].vector));
     expect(vector0).toEqual([1, 2, 3]);
   });
+
+  it("should append generated vectors to a non-nullable schema", async () => {
+    @register("non_nullable_schema_test")
+    class MockEmbeddingFunction extends EmbeddingFunction<string> {
+      ndims() {
+        return 3;
+      }
+      embeddingDataType(): Float {
+        return new Float64();
+      }
+      async computeSourceEmbeddings(data: string[]) {
+        return data.map(() => [1, 2, 3]);
+      }
+    }
+
+    const schema = new Schema([
+      new Field("id", new Int32()),
+      new Field("text", new Utf8()),
+      new Field("type", new Utf8()),
+      new Field(
+        "vector",
+        new FixedSizeList(3, new Field("item", new Float64())),
+      ),
+    ]);
+    const func = new MockEmbeddingFunction();
+    const db = await connect(tmpDir.name);
+    const table = await db.createEmptyTable("test_non_nullable", schema, {
+      embeddingFunction: {
+        function: func,
+        sourceColumn: "text",
+      },
+    });
+
+    const data = [
+      { id: 1, text: "Carrot", type: "vegetable" },
+      { id: 2, text: "Apple", type: "fruit" },
+    ];
+    const buffer = await fromDataToBuffer(
+      data,
+      undefined,
+      await table.schema(),
+    );
+    const generatedTable = tableFromIPC(buffer);
+    const vectorField = generatedTable.schema.fields.find(
+      (field) => field.name === "vector",
+    );
+    expect(vectorField?.nullable).toBe(false);
+
+    await table.add(data);
+
+    const rows = await table.query().toArray();
+    expect(rows).toHaveLength(2);
+    for (const row of rows) {
+      expect([...row.vector]).toEqual([1, 2, 3]);
+    }
+  });
+
   it("should error when appending to a table with an unregistered embedding function", async () => {
     @register("mock")
     class MockEmbeddingFunction extends EmbeddingFunction<string> {

nodejs/__test__/package.test.ts

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright The LanceDB Authors
+
+import packageJson = require("../package.json");
+
+describe("package metadata", () => {
+  it("requires Node.js type declarations compatible with the runtime", () => {
+    expect(packageJson.engines.node).toBe(">= 18");
+    expect(packageJson.peerDependencies["@types/node"]).toBe(">=18");
+    expect(packageJson.peerDependenciesMeta["@types/node"]).toEqual({
+      optional: true,
+    });
+  });
+});

nodejs/__test__/query.test.ts

@@ -110,6 +110,81 @@ describe("Query outputSchema", () => {
   });
 });
 
+describe("Search pagination", () => {
+  let tmpDir: tmp.DirResult;
+  let table: Table;
+
+  beforeEach(async () => {
+    tmpDir = tmp.dirSync({ unsafeCleanup: true });
+    const db = await connect(tmpDir.name);
+    const schema = new Schema([
+      new Field("id", new Int64(), false),
+      new Field("text", new Utf8(), false),
+      new Field(
+        "vector",
+        new FixedSizeList(2, new Field("item", new Float32())),
+        false,
+      ),
+    ]);
+    const data = makeArrowTable(
+      [
+        { id: 1n, text: "common", vector: [0, 0] },
+        { id: 2n, text: "common common", vector: [1, 1] },
+        { id: 3n, text: "common common common", vector: [2, 2] },
+        { id: 4n, text: "common common common common", vector: [3, 3] },
+      ],
+      { schema },
+    );
+    table = await db.createTable("test", data);
+  });
+
+  afterEach(() => {
+    tmpDir.removeCallback();
+  });
+
+  it("applies offset after the vector search limit", async () => {
+    const allResults = await table
+      .vectorSearch([0, 0])
+      .select(["id"])
+      .limit(4)
+      .toArray();
+    const secondPage = await table
+      .vectorSearch([0, 0])
+      .select(["id"])
+      .limit(2)
+      .offset(2)
+      .toArray();
+
+    expect(allResults).toHaveLength(4);
+    expect(secondPage).toHaveLength(2);
+    expect(secondPage.map((row) => row.id)).toEqual(
+      allResults.slice(2, 4).map((row) => row.id),
+    );
+  });
+
+  it("applies offset after the full-text search limit", async () => {
+    await table.createIndex("text", { config: Index.fts() });
+
+    const allResults = await table
+      .search("common", "fts")
+      .select(["id"])
+      .limit(4)
+      .toArray();
+    const secondPage = await table
+      .search("common", "fts")
+      .select(["id"])
+      .limit(2)
+      .offset(2)
+      .toArray();
+
+    expect(allResults).toHaveLength(4);
+    expect(secondPage).toHaveLength(2);
+    expect(secondPage.map((row) => row.id)).toEqual(
+      allResults.slice(2, 4).map((row) => row.id),
+    );
+  });
+});
+
 describe("Query orderBy", () => {
   let tmpDir: tmp.DirResult;
   let table: Table;

nodejs/__test__/registry.test.ts

@@ -106,6 +106,77 @@ describe.each([arrow15, arrow16, arrow17, arrow18])("Registry", (arrow) => {
       'Embedding function with alias "mock-embedding" already exists',
     );
   });
+  test("parseFunctions keeps entries sharing a function name", async () => {
+    class MockEmbeddingFunction extends EmbeddingFunction<string> {
+      ndims() {
+        return 3;
+      }
+      embeddingDataType() {
+        return new arrow.Float32() as apiArrow.Float;
+      }
+      async computeSourceEmbeddings(data: string[]) {
+        return data.map(() => [1, 2, 3]);
+      }
+    }
+    register("mock-embedding")(MockEmbeddingFunction);
+    const parsed = await getRegistry().parseFunctions(
+      new Map([
+        [
+          "embedding_functions",
+          JSON.stringify([
+            {
+              name: "mock-embedding",
+              sourceColumn: "text",
+              vectorColumn: "vector_a",
+              model: {},
+            },
+            {
+              name: "mock-embedding",
+              sourceColumn: "text",
+              vectorColumn: "vector_b",
+              model: {},
+            },
+          ]),
+        ],
+      ]),
+    );
+    expect([...parsed.values()].map((f) => f.vectorColumn)).toEqual([
+      "vector_a",
+      "vector_b",
+    ]);
+
+    // The Python bindings write snake_case keys.
+    const snake = await getRegistry().parseFunctions(
+      new Map([
+        [
+          "embedding_functions",
+          JSON.stringify([
+            {
+              name: "mock-embedding",
+              // biome-ignore lint/style/useNamingConvention: the Python wire spelling
+              source_column: "text",
+              // biome-ignore lint/style/useNamingConvention: the Python wire spelling
+              vector_column: "vector_a",
+              model: {},
+            },
+            {
+              name: "mock-embedding",
+              // biome-ignore lint/style/useNamingConvention: the Python wire spelling
+              source_column: "text",
+              // biome-ignore lint/style/useNamingConvention: the Python wire spelling
+              vector_column: "vector_b",
+              model: {},
+            },
+          ]),
+        ],
+      ]),
+    );
+    expect([...snake.keys()]).toEqual(["vector_a", "vector_b"]);
+    expect([...snake.values()].map((f) => f.sourceColumn)).toEqual([
+      "text",
+      "text",
+    ]);
+  });
   test("schema should contain correct metadata", async () => {
     class MockEmbeddingFunction extends EmbeddingFunction<string> {
       constructor(args: FunctionOptions = {}) {

nodejs/__test__/remote.test.ts

@@ -170,6 +170,38 @@ describe("remote connection", () => {
     );
   });
 
+  it("surfaces JSON server errors from remote table operations", async () => {
+    await withMockDatabase(
+      (req, res) => {
+        const path = req.url ?? "";
+        if (path.endsWith("/describe/")) {
+          res.writeHead(200, { "Content-Type": "application/json" }).end(
+            JSON.stringify({
+              name: "broken_table",
+              version: 1,
+              schema: { fields: [] },
+            }),
+          );
+          return;
+        }
+
+        if (path.endsWith("/count_rows/")) {
+          res
+            .writeHead(400, { "Content-Type": "application/json" })
+            .end(JSON.stringify({ error: "count rows failed" }));
+          return;
+        }
+
+        res.writeHead(404).end();
+      },
+      async (db) => {
+        const table = await db.openTable("broken_table");
+
+        await expect(table.countRows()).rejects.toThrow("count rows failed");
+      },
+    );
+  });
+
   it("should pass on requested extra headers", async () => {
     await withMockDatabase(
       (req, res) => {

nodejs/__test__/table.test.ts

@@ -86,6 +86,44 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
       await expect(table.countRows()).resolves.toBe(3);
     });
 
+    it("should support a foreign Float64 vector schema end to end", async () => {
+      const conn = await connect(tmpDir.name);
+      const schema = new arrow.Schema([
+        new arrow.Field("resource_id", new arrow.Int32(), false),
+        new arrow.Field(
+          "vector",
+          new arrow.FixedSizeList(
+            3,
+            new arrow.Field("value", new arrow.Float64(), true),
+          ),
+          false,
+        ),
+      ]);
+      const data = [
+        {
+          // biome-ignore lint/style/useNamingConvention: matches the reported schema
+          resource_id: 0,
+          vector: [0.1, 0.1, 0.1],
+        },
+      ];
+
+      const resources = await conn.createTable("resources", data, { schema });
+
+      const existing = await resources
+        .query()
+        .where("resource_id = 0")
+        .limit(1)
+        .toArray();
+      expect(existing).toHaveLength(1);
+
+      const matched = await resources
+        .search(Float64Array.from(data[0].vector))
+        .limit(1)
+        .toArray();
+      expect(matched).toHaveLength(1);
+      expect(matched[0]["resource_id"]).toBe(0);
+    });
+
     it("should support branches", async () => {
       await table.add([{ id: 1 }]);
       expect(await table.countRows()).toBe(1);
@@ -239,8 +277,16 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
         },
         numIndices: 0,
         numRows: 3,
-        totalBytes: 44,
+        // Full on-disk size of the two data files, footers and metadata included.
+        totalBytes: 684,
       });
+
+      // Index files count toward totalBytes too (only deletion files and
+      // manifests are excluded).
+      await table.createIndex("id", { config: Index.btree() });
+      const statsWithIndex = await table.stats();
+      expect(statsWithIndex.numIndices).toBe(1);
+      expect(statsWithIndex.totalBytes).toBeGreaterThan(684);
     });
 
     it("should overwrite data if asked", async () => {
@@ -3294,3 +3340,120 @@ describe("LSM merge insert", () => {
     await expect(table.query().useLsm(true).toArray()).rejects.toThrow();
   });
 });
+
+describe("LSM convergence and stats", () => {
+  let tmpDir: tmp.DirResult;
+
+  beforeEach(() => {
+    tmpDir = tmp.dirSync({ unsafeCleanup: true });
+  });
+  afterEach(() => tmpDir.removeCallback());
+
+  async function lsmTable(conn: Connection): Promise<Table> {
+    const table = await conn.createEmptyTable(
+      "t",
+      new arrow.Schema([new arrow.Field("id", new arrow.Utf8(), false)]),
+    );
+    await table.setUnenforcedPrimaryKey("id");
+    await table.setLsmWriteSpec({ specType: "unsharded" });
+    return table;
+  }
+
+  // These four route through the server that owns the MemWAL, so a local table
+  // rejects them rather than answering. What is asserted here is that the
+  // bindings reach the core at all; the behavior against a real endpoint is
+  // covered by the mocked endpoint tests in rust/lancedb/src/remote/table.rs.
+  it("rejects flushLsm on a local table", async () => {
+    const conn = await connect(tmpDir.name);
+    const table = await lsmTable(conn);
+
+    await expect(table.flushLsm()).rejects.toThrow(/not supported/i);
+  });
+
+  it("rejects compactLsm on a local table", async () => {
+    const conn = await connect(tmpDir.name);
+    const table = await lsmTable(conn);
+
+    await expect(table.compactLsm()).rejects.toThrow(/not supported/i);
+  });
+
+  it("rejects getLsmStats on a local table", async () => {
+    const conn = await connect(tmpDir.name);
+    const table = await lsmTable(conn);
+
+    await expect(table.getLsmStats()).rejects.toThrow(/not supported/i);
+    await expect(table.getLsmStats(true)).rejects.toThrow(/not supported/i);
+  });
+
+  it("rejects checkpointLsm on a local table", async () => {
+    const conn = await connect(tmpDir.name);
+    const table = await lsmTable(conn);
+
+    // checkpointLsm seals first, so it surfaces flushLsm's rejection.
+    await expect(table.checkpointLsm()).rejects.toThrow(/not supported/i);
+  });
+});
+
+describe("computed columns", () => {
+  let tmpDir: tmp.DirResult;
+  beforeEach(() => {
+    tmpDir = tmp.dirSync({ unsafeCleanup: true });
+  });
+  afterEach(() => tmpDir.removeCallback());
+
+  it("declares a column and fills it on refresh", async () => {
+    const db = await connect(tmpDir.name);
+    const table = await db.createTable("computed", [{ x: 1 }, { x: 2 }]);
+
+    await table.addColumns({
+      computed: [{ name: "doubled", valueSql: "x * 2" }],
+    });
+    let rows = await table.query().toArray();
+    expect(rows.map((r) => r.doubled)).toEqual([null, null]);
+
+    const result = await table.refreshColumn("doubled");
+    expect(result.rowsFilled).toBe(2);
+
+    rows = await table.query().toArray();
+    expect(rows.map((r) => r.doubled).sort()).toEqual([2, 4]);
+  });
+
+  it("returns a job handle from refreshColumnAsync", async () => {
+    const db = await connect(tmpDir.name);
+    const table = await db.createTable("computed_job", [{ x: 1 }, { x: 2 }]);
+
+    await table.addColumns({
+      computed: [{ name: "doubled", valueSql: "x * 2" }],
+    });
+
+    const job = await table.refreshColumnAsync("doubled");
+    expect(job.id).toBeNull();
+    await job.wait();
+    expect(await job.status()).toBe("finished");
+
+    const rows = await table.query().toArray();
+    expect(rows.map((r) => r.doubled).sort()).toEqual([2, 4]);
+
+    // Bad input rejects at the call, not through the job.
+    await expect(table.refreshColumnAsync("x")).rejects.toThrow(
+      "not a computed column",
+    );
+  });
+
+  it("fills rows added since the last refresh", async () => {
+    const db = await connect(tmpDir.name);
+    const table = await db.createTable("computed_append", [{ x: 1 }]);
+
+    await table.addColumns({
+      computed: [{ name: "doubled", valueSql: "x * 2" }],
+    });
+    await table.refreshColumn("doubled");
+    await table.add([{ x: 5 }]);
+
+    const result = await table.refreshColumn("doubled");
+    expect(result.rowsFilled).toBe(1);
+
+    const rows = await table.query().toArray();
+    expect(rows.map((r) => r.doubled).sort()).toEqual([10, 2]);
+  });
+});

nodejs/lancedb/arrow.ts

@@ -48,7 +48,11 @@ import {
 } from "apache-arrow";
 import { Buffers } from "apache-arrow/data";
 import { type EmbeddingFunction } from "./embedding/embedding_function";
-import { EmbeddingFunctionConfig, getRegistry } from "./embedding/registry";
+import {
+  EmbeddingFunctionConfig,
+  getRegistry,
+  parseEmbeddingMetadata,
+} from "./embedding/registry";
 import {
   sanitizeField,
   sanitizeSchema,
@@ -933,7 +937,7 @@ async function applyEmbeddingsFromMetadata(
 
   for (const functionEntry of functions.values()) {
     const sourceColumn = columns[functionEntry.sourceColumn];
-    const destColumn = functionEntry.vectorColumn ?? "vector";
+    const destColumn = functionEntry.vectorColumn;
     if (sourceColumn === undefined) {
       throw new Error(
         `Cannot apply embedding function because the source column '${functionEntry.sourceColumn}' was not present in the data`,
@@ -1385,11 +1389,10 @@ function validateSchemaEmbeddings(
 
         // Check schema metadata for embedding functions
         if (schema.metadata.has("embedding_functions")) {
-          const embeddings = JSON.parse(
+          const entries = parseEmbeddingMetadata(
             schema.metadata.get("embedding_functions")!,
           );
-          // biome-ignore lint/suspicious/noExplicitAny: we don't know the type of `f`
-          if (embeddings.find((f: any) => f["vectorColumn"] === field.name)) {
+          if (entries.some((f) => f.vectorColumn === field.name)) {
             hasEmbeddingFunction = true;
           }
         }

nodejs/lancedb/connection.ts

@@ -327,6 +327,14 @@ export abstract class Connection {
    */
   abstract dropTable(name: string, namespacePath?: string[]): Promise<void>;
 
+  /**
+   * Start dropping a table and return its cleanup job.
+   *
+   * The table may become unavailable before its data files are removed. Wait
+   * on the returned job to know when cleanup has finished.
+   */
+  abstract dropTableAsync(name: string, namespacePath?: string[]): Promise<Job>;
+
   /**
    * Drop all tables in the database.
    * @param {string[]} namespacePath The namespace path to drop tables from (defaults to root namespace).
@@ -705,6 +713,10 @@ export class LocalConnection extends Connection {
     return this.inner.dropTable(name, namespacePath ?? []);
   }
 
+  async dropTableAsync(name: string, namespacePath?: string[]): Promise<Job> {
+    return this.inner.dropTableAsync(name, namespacePath ?? []);
+  }
+
   async dropAllTables(namespacePath?: string[]): Promise<void> {
     return this.inner.dropAllTables(namespacePath ?? []);
   }

nodejs/lancedb/embedding/registry.ts

@@ -104,41 +104,29 @@ export class EmbeddingFunctionRegistry {
   async parseFunctions(
     this: EmbeddingFunctionRegistry,
     metadata: Map<string, string>,
-  ): Promise<Map<string, EmbeddingFunctionConfig>> {
+  ): Promise<Map<string, ResolvedEmbeddingFunctionConfig>> {
     if (!metadata.has("embedding_functions")) {
       return new Map();
-    } else {
-      type FunctionConfig = {
-        name: string;
-        sourceColumn: string;
-        vectorColumn: string;
-        model: EmbeddingFunction["TOptions"];
-      };
-
-      const functions = <FunctionConfig[]>(
-        JSON.parse(metadata.get("embedding_functions")!)
-      );
-
-      const items: [string, EmbeddingFunctionConfig][] = await Promise.all(
-        functions.map(async (f) => {
-          const fn = this.get(f.name);
-          if (!fn) {
-            throw new Error(`Function "${f.name}" not found in registry`);
-          }
-          const func = await this.get(f.name)!.create(f.model);
-          return [
-            f.name,
-            {
-              sourceColumn: f.sourceColumn,
-              vectorColumn: f.vectorColumn,
-              function: func,
-            },
-          ];
-        }),
-      );
-
-      return new Map(items);
     }
+    const entries = parseEmbeddingMetadata(
+      metadata.get("embedding_functions")!,
+    );
+    const items = await Promise.all(
+      entries.map(async (f): Promise<ResolvedEmbeddingFunctionConfig> => {
+        const fn = this.get(f.name);
+        if (!fn) {
+          throw new Error(`Function "${f.name}" not found in registry`);
+        }
+        const func = await fn.create(f.model);
+        return {
+          sourceColumn: f.sourceColumn,
+          vectorColumn: f.vectorColumn,
+          function: func,
+        };
+      }),
+    );
+    // Keyed by output column: one function may serve several columns.
+    return new Map(items.map((config) => [config.vectorColumn, config]));
   }
   // biome-ignore lint/suspicious/noExplicitAny: <explanation>
   functionToMetadata(conf: EmbeddingFunctionConfig): Record<string, any> {
@@ -218,3 +206,52 @@ export interface EmbeddingFunctionConfig {
   vectorColumn?: string;
   function: EmbeddingFunction;
 }
+
+/** An [EmbeddingFunctionConfig] read back from table metadata, where the
+ * vector column is always recorded. */
+export type ResolvedEmbeddingFunctionConfig = EmbeddingFunctionConfig & {
+  vectorColumn: string;
+};
+
+/** One entry of the `embedding_functions` schema metadata, with the column
+ * keys normalized across the bindings' spellings. */
+export type EmbeddingMetadataEntry = {
+  name: string;
+  sourceColumn: string;
+  vectorColumn: string;
+  model: EmbeddingFunction["TOptions"];
+};
+
+/** The single parser for `embedding_functions` schema metadata: every reader
+ * goes through here, so the wire contract cannot fork between them. */
+export function parseEmbeddingMetadata(json: string): EmbeddingMetadataEntry[] {
+  // The wire format, honestly: the Python bindings write snake_case keys.
+  type Raw = {
+    name: string;
+    sourceColumn?: string;
+    // biome-ignore lint/style/useNamingConvention: the Python wire spelling
+    source_column?: string;
+    vectorColumn?: string;
+    // biome-ignore lint/style/useNamingConvention: the Python wire spelling
+    vector_column?: string;
+    model: EmbeddingFunction["TOptions"];
+  };
+  const entries = <Raw[]>JSON.parse(json);
+  const seen = new Set<string>();
+  return entries.map((f) => {
+    const sourceColumn = f.sourceColumn ?? f.source_column;
+    const vectorColumn = f.vectorColumn ?? f.vector_column;
+    if (sourceColumn === undefined || vectorColumn === undefined) {
+      throw new Error(
+        `Embedding function "${f.name}" metadata names no source or vector column`,
+      );
+    }
+    if (seen.has(vectorColumn)) {
+      throw new Error(
+        `Multiple embedding configs claim vector column "${vectorColumn}"`,
+      );
+    }
+    seen.add(vectorColumn);
+    return { name: f.name, sourceColumn, vectorColumn, model: f.model };
+  });
+}

nodejs/lancedb/index.ts

@@ -50,6 +50,7 @@ export {
   MergeResult,
   AddResult,
   AddColumnsResult,
+  RefreshColumnResult,
   AlterColumnsResult,
   UpdateFieldMetadataResult,
   DeleteResult,
@@ -146,6 +147,10 @@ export {
   FtsToken,
   TokenizeTableOptions,
   LsmWriteSpec,
+  LsmStats,
+  BucketStats,
+  GenerationStats,
+  MemtableStats,
   ColumnAlteration,
   FieldMetadataUpdate,
 } from "./table";

nodejs/lancedb/sanitize.ts

@@ -9,7 +9,7 @@
 // comes from the exact same library instance.  This is not always the case
 // and so we must sanitize the input to ensure that it is compatible.
 
-import { BufferType, Data } from "apache-arrow";
+import { BufferType, Data, Vector } from "apache-arrow";
 import type { IntBitWidth, TKeys, TimeBitWidth } from "apache-arrow/type";
 import {
   Binary,
@@ -74,6 +74,20 @@ import {
   Utf8,
 } from "./arrow";
 
+type SanitizationContext = {
+  types: WeakMap<object, DataType>;
+  vectors: WeakMap<object, Vector>;
+  data: WeakMap<object, Data<DataType>>;
+};
+
+function createSanitizationContext(): SanitizationContext {
+  return {
+    types: new WeakMap(),
+    vectors: new WeakMap(),
+    data: new WeakMap(),
+  };
+}
+
 export function sanitizeMetadata(
   metadataLike?: unknown,
 ): Map<string, string> | undefined {
@@ -186,6 +200,13 @@ export function sanitizeInterval(typeLike: object) {
 }
 
 export function sanitizeList(typeLike: object) {
+  return sanitizeListWithContext(typeLike, createSanitizationContext());
+}
+
+function sanitizeListWithContext(
+  typeLike: object,
+  context: SanitizationContext,
+) {
   if (!("children" in typeLike) || !Array.isArray(typeLike.children)) {
     throw Error(
       "Expected a List type to have an array-like `children` property",
@@ -194,19 +215,35 @@ export function sanitizeList(typeLike: object) {
   if (typeLike.children.length !== 1) {
     throw Error("Expected a List type to have exactly one child");
   }
-  return new List(sanitizeField(typeLike.children[0]));
+  return new List(sanitizeFieldWithContext(typeLike.children[0], context));
 }
 
 export function sanitizeStruct(typeLike: object) {
+  return sanitizeStructWithContext(typeLike, createSanitizationContext());
+}
+
+function sanitizeStructWithContext(
+  typeLike: object,
+  context: SanitizationContext,
+) {
   if (!("children" in typeLike) || !Array.isArray(typeLike.children)) {
     throw Error(
       "Expected a Struct type to have an array-like `children` property",
     );
   }
-  return new Struct(typeLike.children.map((child) => sanitizeField(child)));
+  return new Struct(
+    typeLike.children.map((child) => sanitizeFieldWithContext(child, context)),
+  );
 }
 
 export function sanitizeUnion(typeLike: object) {
+  return sanitizeUnionWithContext(typeLike, createSanitizationContext());
+}
+
+function sanitizeUnionWithContext(
+  typeLike: object,
+  context: SanitizationContext,
+) {
   if (
     !("typeIds" in typeLike) ||
     !("mode" in typeLike) ||
@@ -226,7 +263,7 @@ export function sanitizeUnion(typeLike: object) {
     typeLike.mode,
     // biome-ignore lint/suspicious/noExplicitAny: skip
     typeLike.typeIds as any,
-    typeLike.children.map((child) => sanitizeField(child)),
+    typeLike.children.map((child) => sanitizeFieldWithContext(child, context)),
   );
 }
 
@@ -234,6 +271,19 @@ export function sanitizeTypedUnion(
   typeLike: object,
   // eslint-disable-next-line @typescript-eslint/naming-convention
   UnionType: typeof DenseUnion | typeof SparseUnion,
+) {
+  return sanitizeTypedUnionWithContext(
+    typeLike,
+    UnionType,
+    createSanitizationContext(),
+  );
+}
+
+function sanitizeTypedUnionWithContext(
+  typeLike: object,
+  // eslint-disable-next-line @typescript-eslint/naming-convention
+  UnionType: typeof DenseUnion | typeof SparseUnion,
+  context: SanitizationContext,
 ) {
   if (!("typeIds" in typeLike)) {
     throw Error(
@@ -248,7 +298,7 @@ export function sanitizeTypedUnion(
 
   return new UnionType(
     typeLike.typeIds as Int32Array | number[],
-    typeLike.children.map((child) => sanitizeField(child)),
+    typeLike.children.map((child) => sanitizeFieldWithContext(child, context)),
   );
 }
 
@@ -262,6 +312,16 @@ export function sanitizeFixedSizeBinary(typeLike: object) {
 }
 
 export function sanitizeFixedSizeList(typeLike: object) {
+  return sanitizeFixedSizeListWithContext(
+    typeLike,
+    createSanitizationContext(),
+  );
+}
+
+function sanitizeFixedSizeListWithContext(
+  typeLike: object,
+  context: SanitizationContext,
+) {
   if (!("listSize" in typeLike) || typeof typeLike.listSize !== "number") {
     throw Error("Expected a FixedSizeList type to have a `listSize` property");
   }
@@ -275,11 +335,18 @@ export function sanitizeFixedSizeList(typeLike: object) {
   }
   return new FixedSizeList(
     typeLike.listSize,
-    sanitizeField(typeLike.children[0]),
+    sanitizeFieldWithContext(typeLike.children[0], context),
   );
 }
 
 export function sanitizeMap(typeLike: object) {
+  return sanitizeMapWithContext(typeLike, createSanitizationContext());
+}
+
+function sanitizeMapWithContext(
+  typeLike: object,
+  context: SanitizationContext,
+) {
   if (!("children" in typeLike) || !Array.isArray(typeLike.children)) {
     throw Error(
       "Expected a Map type to have an array-like `children` property",
@@ -292,7 +359,10 @@ export function sanitizeMap(typeLike: object) {
     throw Error("Expected a Map type to have exactly one child");
   }
 
-  return new Map_(sanitizeField(typeLike.children[0]), typeLike.keysSorted);
+  return new Map_(
+    sanitizeFieldWithContext(typeLike.children[0], context),
+    typeLike.keysSorted,
+  );
 }
 
 export function sanitizeDuration(typeLike: object) {
@@ -303,6 +373,13 @@ export function sanitizeDuration(typeLike: object) {
 }
 
 export function sanitizeDictionary(typeLike: object) {
+  return sanitizeDictionaryWithContext(typeLike, createSanitizationContext());
+}
+
+function sanitizeDictionaryWithContext(
+  typeLike: object,
+  context: SanitizationContext,
+) {
   if (!("id" in typeLike) || typeof typeLike.id !== "number") {
     throw Error("Expected a Dictionary type to have an `id` property");
   }
@@ -316,8 +393,8 @@ export function sanitizeDictionary(typeLike: object) {
     throw Error("Expected a Dictionary type to have an `isOrdered` property");
   }
   return new Dictionary(
-    sanitizeType(typeLike.dictionary),
-    sanitizeType(typeLike.indices) as TKeys,
+    sanitizeTypeWithContext(typeLike.dictionary, context),
+    sanitizeTypeWithContext(typeLike.indices, context) as TKeys,
     typeLike.id,
     typeLike.isOrdered,
   );
@@ -325,12 +402,23 @@ export function sanitizeDictionary(typeLike: object) {
 
 // biome-ignore lint/suspicious/noExplicitAny: skip
 export function sanitizeType(typeLike: unknown): DataType<any> {
+  return sanitizeTypeWithContext(typeLike, createSanitizationContext());
+}
+
+function sanitizeTypeWithContext(
+  typeLike: unknown,
+  context: SanitizationContext,
+): DataType {
   if (typeof typeLike === "string") {
     return dataTypeFromName(typeLike);
   }
   if (typeof typeLike !== "object" || typeLike === null) {
     throw Error("Expected a Type but object was null/undefined");
   }
+  const cached = context.types.get(typeLike);
+  if (cached !== undefined) {
+    return cached;
+  }
   if (
     !("typeId" in typeLike) ||
     !(
@@ -349,6 +437,16 @@ export function sanitizeType(typeLike: unknown): DataType<any> {
     throw Error("Type's typeId property was not a function or number");
   }
 
+  const type = sanitizeTypeById(typeLike, typeId, context);
+  context.types.set(typeLike, type);
+  return type;
+}
+
+function sanitizeTypeById(
+  typeLike: object,
+  typeId: Type,
+  context: SanitizationContext,
+): DataType {
   switch (typeId) {
     case Type.NONE:
       throw Error("Received a Type with a typeId of NONE");
@@ -375,21 +473,21 @@ export function sanitizeType(typeLike: unknown): DataType<any> {
     case Type.Interval:
       return sanitizeInterval(typeLike);
     case Type.List:
-      return sanitizeList(typeLike);
+      return sanitizeListWithContext(typeLike, context);
     case Type.Struct:
-      return sanitizeStruct(typeLike);
+      return sanitizeStructWithContext(typeLike, context);
     case Type.Union:
-      return sanitizeUnion(typeLike);
+      return sanitizeUnionWithContext(typeLike, context);
     case Type.FixedSizeBinary:
       return sanitizeFixedSizeBinary(typeLike);
     case Type.FixedSizeList:
-      return sanitizeFixedSizeList(typeLike);
+      return sanitizeFixedSizeListWithContext(typeLike, context);
     case Type.Map:
-      return sanitizeMap(typeLike);
+      return sanitizeMapWithContext(typeLike, context);
     case Type.Duration:
       return sanitizeDuration(typeLike);
     case Type.Dictionary:
-      return sanitizeDictionary(typeLike);
+      return sanitizeDictionaryWithContext(typeLike, context);
     case Type.Int8:
       return new Int8();
     case Type.Int16:
@@ -433,9 +531,9 @@ export function sanitizeType(typeLike: unknown): DataType<any> {
     case Type.TimestampSecond:
       return sanitizeTypedTimestamp(typeLike, TimestampSecond);
     case Type.DenseUnion:
-      return sanitizeTypedUnion(typeLike, DenseUnion);
+      return sanitizeTypedUnionWithContext(typeLike, DenseUnion, context);
     case Type.SparseUnion:
-      return sanitizeTypedUnion(typeLike, SparseUnion);
+      return sanitizeTypedUnionWithContext(typeLike, SparseUnion, context);
     case Type.IntervalDayTime:
       return new IntervalDayTime();
     case Type.IntervalYearMonth:
@@ -454,6 +552,13 @@ export function sanitizeType(typeLike: unknown): DataType<any> {
 }
 
 export function sanitizeField(fieldLike: unknown): Field {
+  return sanitizeFieldWithContext(fieldLike, createSanitizationContext());
+}
+
+function sanitizeFieldWithContext(
+  fieldLike: unknown,
+  context: SanitizationContext,
+): Field {
   if (fieldLike instanceof Field) {
     return fieldLike;
   }
@@ -471,7 +576,7 @@ export function sanitizeField(fieldLike: unknown): Field {
   }
   let type: DataType;
   try {
-    type = sanitizeType(fieldLike.type);
+    type = sanitizeTypeWithContext(fieldLike.type, context);
   } catch (error: unknown) {
     throw Error(
       `Unable to sanitize type for field: ${fieldLike.name} due to error: ${error}`,
@@ -501,6 +606,13 @@ export function sanitizeField(fieldLike: unknown): Field {
  * than lancedb is using.
  */
 export function sanitizeSchema(schemaLike: SchemaLike): Schema {
+  return sanitizeSchemaWithContext(schemaLike, createSanitizationContext());
+}
+
+function sanitizeSchemaWithContext(
+  schemaLike: SchemaLike,
+  context: SanitizationContext,
+): Schema {
   if (schemaLike instanceof Schema) {
     return schemaLike;
   }
@@ -522,7 +634,7 @@ export function sanitizeSchema(schemaLike: SchemaLike): Schema {
     );
   }
   const sanitizedFields = schemaLike.fields.map((field) =>
-    sanitizeField(field),
+    sanitizeFieldWithContext(field, context),
   );
   return new Schema(sanitizedFields, metadata);
 }
@@ -544,13 +656,18 @@ export function sanitizeTable(tableLike: TableLike): Table {
       "The table passed in does not appear to be a table (no 'columns' property)",
     );
   }
-  const schema = sanitizeSchema(tableLike.schema);
-
-  const batches = tableLike.batches.map(sanitizeRecordBatch);
+  const context = createSanitizationContext();
+  const schema = sanitizeSchemaWithContext(tableLike.schema, context);
+  const batches = tableLike.batches.map((batch) =>
+    sanitizeRecordBatch(batch, context),
+  );
   return new Table(schema, batches);
 }
 
-function sanitizeRecordBatch(batchLike: RecordBatchLike): RecordBatch {
+function sanitizeRecordBatch(
+  batchLike: RecordBatchLike,
+  context: SanitizationContext,
+): RecordBatch {
   if (batchLike instanceof RecordBatch) {
     return batchLike;
   }
@@ -567,19 +684,43 @@ function sanitizeRecordBatch(batchLike: RecordBatchLike): RecordBatch {
       "The record batch passed in does not appear to be a record batch (no 'data' property)",
     );
   }
-  const schema = sanitizeSchema(batchLike.schema);
-  const data = sanitizeData(batchLike.data);
+  const schema = sanitizeSchemaWithContext(batchLike.schema, context);
+  const data = sanitizeData(batchLike.data, context) as Data<Struct>;
   return new RecordBatch(schema, data);
 }
+
+type DictionaryVectorLike = {
+  data: readonly DataLike[];
+};
+
+type DictionaryDataLike = DataLike & {
+  dictionary?: DictionaryVectorLike;
+};
+
 function sanitizeData(
   dataLike: DataLike,
-  // biome-ignore lint/suspicious/noExplicitAny: <explanation>
-): import("apache-arrow").Data<Struct<any>> {
+  context: SanitizationContext,
+): Data<DataType> {
   if (dataLike instanceof Data) {
     return dataLike;
   }
-  return new Data(
-    dataLike.type,
+  const cachedData = context.data.get(dataLike);
+  if (cachedData !== undefined) {
+    return cachedData;
+  }
+  const dictionaryLike = (dataLike as DictionaryDataLike).dictionary;
+  let dictionary: Vector | undefined;
+  if (dictionaryLike !== undefined) {
+    dictionary = context.vectors.get(dictionaryLike);
+    if (dictionary === undefined) {
+      dictionary = new Vector(
+        dictionaryLike.data.map((data) => sanitizeData(data, context)),
+      );
+      context.vectors.set(dictionaryLike, dictionary);
+    }
+  }
+  const data = new Data(
+    sanitizeTypeWithContext(dataLike.type, context),
     dataLike.offset,
     dataLike.length,
     dataLike.nullCount,
@@ -589,7 +730,11 @@ function sanitizeData(
       [BufferType.VALIDITY]: dataLike.nullBitmap,
       [BufferType.TYPE]: dataLike.typeIds,
     },
+    dataLike.children.map((child) => sanitizeData(child, context)),
+    dictionary,
   );
+  context.data.set(dataLike, data);
+  return data;
 }
 
 const constructorsByTypeName = {

nodejs/lancedb/table.ts

@@ -31,8 +31,10 @@ import {
   IndexConfig,
   IndexStatistics,
   Job,
+  LsmStats,
   Branches as NativeBranches,
   OptimizeStats,
+  RefreshColumnResult,
   TableStatistics,
   Tags,
   UpdateFieldMetadataResult,
@@ -49,6 +51,12 @@ import {
 import { sanitizeType } from "./sanitize";
 import { IntoSql, toSQL } from "./util";
 export { IndexConfig } from "./native";
+export {
+  BucketStats,
+  GenerationStats,
+  LsmStats,
+  MemtableStats,
+} from "./native";
 
 /**
  * Progress snapshot for a write operation, delivered to the `progress`
@@ -197,7 +205,11 @@ export interface LsmWriteSpec {
   column?: string;
   /** Bucket variant: the number of buckets, in `[1, 1024]`. */
   numBuckets?: number;
-  /** Names of indexes the MemWAL should keep up to date during writes. */
+  /**
+   * Indexes the MemWAL keeps up to date. Omit to maintain every supported
+   * index, resolved on install — a snapshot, so indexes created later are not
+   * maintained. Pass `[]` for none.
+   */
   maintainedIndexes?: string[];
   /** Default `ShardWriter` configuration recorded in the MemWAL index. */
   writerConfigDefaults?: Record<string, string>;
@@ -521,18 +533,75 @@ export abstract class Table {
   abstract vectorSearch(vector: IntoVector | MultiVector): VectorQuery;
   /**
    * Add new columns with defined values.
+   *
+   * The `{ computed }` form stores the expression rather than evaluating it
+   * now: the column is committed with no values, and rows get them from
+   * {@link Table#refreshColumn}. Declaring one therefore costs the same on a
+   * large table as on an empty one.
+   *
+   * A refresh does not revisit rows it has already filled, so mutating an
+   * input leaves the value computed at fill time; recomputing means dropping
+   * the column and declaring it again. While a declaration reads a column,
+   * that column cannot be renamed, retyped or dropped.
+   *
+   * On LanceDB Cloud and Enterprise the expression is planned by the
+   * server, and the refresh runs as a server job -- see
+   * {@link Table#refreshColumnAsync}.
    * @param {AddColumnsSql[] | Field | Field[] | Schema} newColumnTransforms Either:
    *   - An array of objects with column names and SQL expressions to calculate values
    *   - A single Arrow Field defining one column with its data type (column will be initialized with null values)
    *   - An array of Arrow Fields defining columns with their data types (columns will be initialized with null values)
    *   - An Arrow Schema defining columns with their data types (columns will be initialized with null values)
+   *   - `{ computed }`, declaring columns defined by a SQL expression whose type and inputs are derived from it
    * @returns {Promise<AddColumnsResult>} A promise that resolves to an object
    * containing the new version number of the table after adding the columns.
+   * @example
+   * ```ts
+   * await table.addColumns({ computed: [{ name: "doubled", valueSql: "x * 2" }] });
+   * const { rowsFilled } = await table.refreshColumn("doubled");
+   * ```
    */
   abstract addColumns(
-    newColumnTransforms: AddColumnsSql[] | Field | Field[] | Schema,
+    newColumnTransforms:
+      | AddColumnsSql[]
+      | Field
+      | Field[]
+      | Schema
+      | { computed: AddColumnsSql[] },
   ): Promise<AddColumnsResult>;
 
+  /**
+   * Fill the rows of a computed column that hold no value yet.
+   *
+   * Rows appended since the last refresh are filled by the next one; rows
+   * already filled are left as they are, so the call is idempotent and does
+   * not observe a mutated input. Local tables only: a remote refresh runs
+   * as a server job, through {@link Table#refreshColumnAsync}.
+   * @param {string} column The name of the computed column to fill.
+   * @returns {Promise<RefreshColumnResult>} A promise that resolves to the
+   * number of rows filled and the new version number of the table.
+   */
+  abstract refreshColumn(column: string): Promise<RefreshColumnResult>;
+
+  /**
+   * Like {@link Table#refreshColumn}, but returns a handle to the refresh
+   * job instead of blocking until it completes.
+   *
+   * The job may already be complete when returned; callers must not assume
+   * the column is filled until {@link Job.wait} resolves. Invalid input --
+   * an unknown column, or one that is not computed -- rejects here rather
+   * than failing the job. On local tables the job runs in-process; on
+   * LanceDB Cloud and Enterprise it is the server's backfill job.
+   * @param {string} column The name of the computed column to fill.
+   * @example
+   * ```ts
+   * const job = await table.refreshColumnAsync("doubled");
+   * await job.wait();
+   * console.log(await job.status()); // "finished"
+   * ```
+   */
+  abstract refreshColumnAsync(column: string): Promise<Job>;
+
   /**
    * Alter the name or nullability of columns.
    * @param {ColumnAlteration[]} columnAlterations One or more alterations to
@@ -595,6 +664,11 @@ export abstract class Table {
    * All variants require the table to have an unenforced primary key
    * ({@link Table#setUnenforcedPrimaryKey}); bucket sharding additionally
    * requires it to be the single column being bucketed.
+   *
+   * Omitting `maintainedIndexes` maintains every index on the table, resolved
+   * here, failing if one cannot be maintained — name them to install anyway.
+   * Naming them pins an exact set, and a still-building index is rejected
+   * rather than quietly omitted.
    * @param {LsmWriteSpec} spec The sharding spec to install.
    * @returns {Promise<void>}
    * @example
@@ -622,9 +696,10 @@ export abstract class Table {
    *
    * Resolves to `undefined` when the MemWAL LSM write path is not enabled (no
    * spec has been set, or it was removed with {@link Table#unsetLsmWriteSpec}).
-   * The returned spec — including its `maintainedIndexes` and
-   * `writerConfigDefaults` — mirrors what was passed to
-   * {@link Table#setLsmWriteSpec}.
+   * The returned spec mirrors what was passed to
+   * {@link Table#setLsmWriteSpec}, except that `maintainedIndexes` always
+   * reports the concrete list resolved when the spec was set — `undefined`
+   * never round-trips.
    * @returns {Promise<LsmWriteSpec | undefined>}
    */
   abstract getLsmWriteSpec(): Promise<LsmWriteSpec | undefined>;
@@ -638,6 +713,59 @@ export abstract class Table {
    * @returns {Promise<void>}
    */
   abstract closeLsmWriters(): Promise<void>;
+  /**
+   * Seal every bucket's active memtable into a new L0 generation.
+   *
+   * Returns once the seal is committed. Sealing an empty memtable is a no-op,
+   * so this is safe to call repeatedly.
+   * @returns {Promise<void>}
+   */
+  abstract flushLsm(): Promise<void>;
+  /**
+   * Trigger a background L0 → base compaction pass per bucket.
+   *
+   * Returns once the passes are *dispatched*, not once they finish — watch
+   * {@link Table#getLsmStats} for progress, or use
+   * {@link Table#checkpointLsm} to wait for convergence.
+   * @returns {Promise<void>}
+   */
+  abstract compactLsm(): Promise<void>;
+  /**
+   * Converge this table's LSM write path into its base table.
+   *
+   * Seals once, then triggers compaction and polls until the L0 that existed
+   * at the start is gone. The target set is fixed at the start, so
+   * generations created *during* the checkpoint are ignored — that is what
+   * lets it terminate under write load, and what makes it best-effort: it
+   * converges the fresh tier as of some instant. Idempotent, abandonable at
+   * any point, and safe to run on a cadence.
+   *
+   * There is no liveness bound — the compactor pool is shared across tables,
+   * so a checkpoint queued behind unrelated work looks exactly like one that
+   * is merging. The caller owns the deadline.
+   * @returns {Promise<void>}
+   * @example
+   * ```ts
+   * const before = await table.getLsmStats();
+   * await table.checkpointLsm();
+   * const after = await table.getLsmStats();
+   * ```
+   */
+  abstract checkpointLsm(): Promise<void>;
+  /**
+   * Read live per-bucket LSM state.
+   *
+   * Answers "how far behind is my fresh tier", "which bucket is hot", and
+   * "why is my fresh-tier vector search brute-force". Mutates no table state.
+   *
+   * Resolves to `undefined` only when the LSM write path is not enabled.
+   * @param {boolean} includeGenerationRows Also count rows per L0 generation.
+   *   Off by default because each count opens an uncached Lance dataset.
+   * @returns {Promise<LsmStats | undefined>}
+   */
+  abstract getLsmStats(
+    includeGenerationRows?: boolean,
+  ): Promise<LsmStats | undefined>;
   /** Retrieve the version of the table */
 
   abstract version(): Promise<number>;
@@ -1078,8 +1206,22 @@ export class LocalTable extends Table {
   // TODO: Support BatchUDF
 
   async addColumns(
-    newColumnTransforms: AddColumnsSql[] | Field | Field[] | Schema,
+    newColumnTransforms:
+      | AddColumnsSql[]
+      | Field
+      | Field[]
+      | Schema
+      | { computed: AddColumnsSql[] },
   ): Promise<AddColumnsResult> {
+    // Columns defined by an expression are declared, not materialized here.
+    if (
+      typeof newColumnTransforms === "object" &&
+      !Array.isArray(newColumnTransforms) &&
+      "computed" in newColumnTransforms
+    ) {
+      return await this.inner.addComputedColumns(newColumnTransforms.computed);
+    }
+
     // Handle single Field -> convert to array of Fields
     if (newColumnTransforms instanceof Field) {
       newColumnTransforms = [newColumnTransforms];
@@ -1114,6 +1256,14 @@ export class LocalTable extends Table {
     throw new Error("Invalid input type for addColumns");
   }
 
+  async refreshColumn(column: string): Promise<RefreshColumnResult> {
+    return await this.inner.refreshColumn(column);
+  }
+
+  async refreshColumnAsync(column: string): Promise<Job> {
+    return await this.inner.refreshColumnAsync(column);
+  }
+
   async alterColumns(
     columnAlterations: ColumnAlteration[],
   ): Promise<AlterColumnsResult> {
@@ -1176,6 +1326,24 @@ export class LocalTable extends Table {
     return await this.inner.closeLsmWriters();
   }
 
+  async flushLsm(): Promise<void> {
+    return await this.inner.flushLsm();
+  }
+
+  async compactLsm(): Promise<void> {
+    return await this.inner.compactLsm();
+  }
+
+  async checkpointLsm(): Promise<void> {
+    return await this.inner.checkpointLsm();
+  }
+
+  async getLsmStats(
+    includeGenerationRows: boolean = false,
+  ): Promise<LsmStats | undefined> {
+    return (await this.inner.getLsmStats(includeGenerationRows)) ?? undefined;
+  }
+
   async version(): Promise<number> {
     return await this.inner.version();
   }

nodejs/npm/darwin-arm64/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-darwin-arm64",
-	"version": "0.37.1-beta.0",
+	"version": "0.38.0-beta.3",
 	"os": ["darwin"],
 	"cpu": ["arm64"],
 	"main": "lancedb.darwin-arm64.node",

nodejs/npm/linux-arm64-gnu/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-arm64-gnu",
-	"version": "0.37.1-beta.0",
+	"version": "0.38.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["arm64"],
 	"main": "lancedb.linux-arm64-gnu.node",

nodejs/npm/linux-arm64-musl/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-arm64-musl",
-	"version": "0.37.1-beta.0",
+	"version": "0.38.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["arm64"],
 	"main": "lancedb.linux-arm64-musl.node",

nodejs/npm/linux-x64-gnu/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-x64-gnu",
-	"version": "0.37.1-beta.0",
+	"version": "0.38.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["x64"],
 	"main": "lancedb.linux-x64-gnu.node",

nodejs/npm/linux-x64-musl/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-linux-x64-musl",
-	"version": "0.37.1-beta.0",
+	"version": "0.38.0-beta.3",
 	"os": ["linux"],
 	"cpu": ["x64"],
 	"main": "lancedb.linux-x64-musl.node",

nodejs/npm/win32-arm64-msvc/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lancedb/lancedb-win32-arm64-msvc",
-  "version": "0.37.1-beta.0",
+  "version": "0.38.0-beta.3",
   "os": [
     "win32"
   ],

nodejs/npm/win32-x64-msvc/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@lancedb/lancedb-win32-x64-msvc",
-	"version": "0.37.1-beta.0",
+	"version": "0.38.0-beta.3",
 	"os": ["win32"],
 	"cpu": ["x64"],
 	"main": "lancedb.win32-x64-msvc.node",

nodejs/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@lancedb/lancedb",
-  "version": "0.37.1-beta.0",
+  "version": "0.38.0-beta.3",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@lancedb/lancedb",
-      "version": "0.37.1-beta.0",
+      "version": "0.38.0-beta.3",
       "cpu": [
         "x64",
         "arm64"
@@ -55,7 +55,13 @@
         "openai": "4.29.2"
       },
       "peerDependencies": {
+        "@types/node": ">=18",
         "apache-arrow": ">=15.0.0 <=18.1.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/node": {
+          "optional": true
+        }
       }
     },
     "node_modules/@aws-crypto/crc32": {

nodejs/package.json

@@ -11,7 +11,7 @@
     "ann"
   ],
   "private": false,
-  "version": "0.37.1-beta.0",
+  "version": "0.38.0-beta.3",
   "main": "dist/index.js",
   "exports": {
     ".": "./dist/index.js",
@@ -101,6 +101,12 @@
     "openai": "4.29.2"
   },
   "peerDependencies": {
+    "@types/node": ">=18",
     "apache-arrow": ">=15.0.0 <=18.1.0"
+  },
+  "peerDependenciesMeta": {
+    "@types/node": {
+      "optional": true
+    }
   }
 }

nodejs/src/connection.rs

@@ -334,6 +334,22 @@ impl Connection {
             .default_error()
     }
 
+    /// Start dropping a table and return its cleanup job.
+    #[napi(catch_unwind)]
+    pub async fn drop_table_async(
+        &self,
+        name: String,
+        namespace_path: Option<Vec<String>>,
+    ) -> napi::Result<crate::job::Job> {
+        let ns = namespace_path.unwrap_or_default();
+        let job = self
+            .get_inner()?
+            .drop_table_async(&name, &ns)
+            .await
+            .default_error()?;
+        Ok(crate::job::Job::new(job))
+    }
+
     #[napi(catch_unwind)]
     pub async fn drop_all_tables(&self, namespace_path: Option<Vec<String>>) -> napi::Result<()> {
         let ns = namespace_path.unwrap_or_default();

nodejs/src/table.rs

@@ -347,6 +347,40 @@ impl Table {
         Ok(res.into())
     }
 
+    #[napi(catch_unwind)]
+    pub async fn add_computed_columns(
+        &self,
+        columns: Vec<AddColumnsSql>,
+    ) -> napi::Result<AddColumnsResult> {
+        let table = self.inner_ref()?;
+        let mut builder = table.add_columns();
+        for column in columns {
+            builder = builder.computed(column.name, column.value_sql);
+        }
+        let res = builder.execute().await.default_error()?;
+        Ok(res.into())
+    }
+
+    #[napi(catch_unwind)]
+    pub async fn refresh_column(&self, column: String) -> napi::Result<RefreshColumnResult> {
+        let res = self
+            .inner_ref()?
+            .refresh_column(column)
+            .await
+            .default_error()?;
+        Ok(res.into())
+    }
+
+    #[napi(catch_unwind)]
+    pub async fn refresh_column_async(&self, column: String) -> napi::Result<crate::job::Job> {
+        let job = self
+            .inner_ref()?
+            .refresh_column_async(column)
+            .await
+            .default_error()?;
+        Ok(crate::job::Job::new(job))
+    }
+
     #[napi(catch_unwind)]
     pub async fn add_columns_with_schema(
         &self,
@@ -463,6 +497,34 @@ impl Table {
         self.inner_ref()?.close_lsm_writers().await.default_error()
     }
 
+    #[napi(catch_unwind)]
+    pub async fn flush_lsm(&self) -> napi::Result<()> {
+        self.inner_ref()?.flush_lsm().await.default_error()
+    }
+
+    #[napi(catch_unwind)]
+    pub async fn compact_lsm(&self) -> napi::Result<()> {
+        self.inner_ref()?.compact_lsm().await.default_error()
+    }
+
+    #[napi(catch_unwind)]
+    pub async fn checkpoint_lsm(&self) -> napi::Result<()> {
+        self.inner_ref()?.checkpoint_lsm().await.default_error()
+    }
+
+    #[napi(catch_unwind)]
+    pub async fn get_lsm_stats(
+        &self,
+        include_generation_rows: bool,
+    ) -> napi::Result<Option<LsmStats>> {
+        let stats = self
+            .inner_ref()?
+            .get_lsm_stats(include_generation_rows)
+            .await
+            .default_error()?;
+        Ok(stats.map(LsmStats::from))
+    }
+
     #[napi(catch_unwind)]
     pub async fn version(&self) -> napi::Result<i64> {
         self.inner_ref()?
@@ -772,7 +834,8 @@ pub struct LsmWriteSpec {
     pub column: Option<String>,
     /// Bucket variant: the number of buckets, in `[1, 1024]`.
     pub num_buckets: Option<u32>,
-    /// Names of indexes the MemWAL should keep up to date during writes.
+    /// Indexes the MemWAL keeps up to date. Omitted resolves every
+    /// maintainable index on install; an empty array means none.
     pub maintained_indexes: Option<Vec<String>>,
     /// Default `ShardWriter` configuration recorded in the MemWAL index.
     pub writer_config_defaults: Option<HashMap<String, String>>,
@@ -782,7 +845,6 @@ impl TryFrom<LsmWriteSpec> for lancedb::table::LsmWriteSpec {
     type Error = napi::Error;
 
     fn try_from(value: LsmWriteSpec) -> napi::Result<Self> {
-        let maintained = value.maintained_indexes.unwrap_or_default();
         let writer_config_defaults = value.writer_config_defaults.unwrap_or_default();
         let spec = match value.spec_type.as_str() {
             "bucket" => {
@@ -809,7 +871,7 @@ impl TryFrom<LsmWriteSpec> for lancedb::table::LsmWriteSpec {
             }
         };
         Ok(spec
-            .with_maintained_indexes(maintained)
+            .with_maintained_indexes(value.maintained_indexes)
             .with_writer_config_defaults(writer_config_defaults))
     }
 }
@@ -827,7 +889,7 @@ impl From<lancedb::table::LsmWriteSpec> for LsmWriteSpec {
                 spec_type: "bucket".to_string(),
                 column: Some(column),
                 num_buckets: Some(num_buckets),
-                maintained_indexes: Some(maintained_indexes),
+                maintained_indexes,
                 writer_config_defaults: Some(writer_config_defaults),
             },
             Native::Identity {
@@ -838,7 +900,7 @@ impl From<lancedb::table::LsmWriteSpec> for LsmWriteSpec {
                 spec_type: "identity".to_string(),
                 column: Some(column),
                 num_buckets: None,
-                maintained_indexes: Some(maintained_indexes),
+                maintained_indexes,
                 writer_config_defaults: Some(writer_config_defaults),
             },
             Native::Unsharded {
@@ -848,13 +910,136 @@ impl From<lancedb::table::LsmWriteSpec> for LsmWriteSpec {
                 spec_type: "unsharded".to_string(),
                 column: None,
                 num_buckets: None,
-                maintained_indexes: Some(maintained_indexes),
+                maintained_indexes,
                 writer_config_defaults: Some(writer_config_defaults),
             },
         }
     }
 }
 
+/// One flushed L0 generation.
+#[napi(object)]
+#[derive(Clone, Debug)]
+pub struct GenerationStats {
+    /// The generation number. Increases as memtables are sealed into L0.
+    pub generation: i64,
+    /// On-disk size of the generation.
+    pub bytes: i64,
+    /// Present only when `includeGenerationRows` was requested. Off by default
+    /// because each count opens an uncached Lance dataset.
+    pub rows: Option<i64>,
+}
+
+impl From<lancedb::table::GenerationStats> for GenerationStats {
+    fn from(g: lancedb::table::GenerationStats) -> Self {
+        Self {
+            generation: g.generation as i64,
+            bytes: g.bytes as i64,
+            rows: g.rows.map(|r| r as i64),
+        }
+    }
+}
+
+/// One in-memory memtable.
+#[napi(object)]
+#[derive(Clone, Debug)]
+pub struct MemtableStats {
+    /// The generation this memtable will become once sealed.
+    pub generation: i64,
+    /// Rows currently buffered.
+    pub rows: i64,
+    /// Estimated in-memory size.
+    pub bytes: i64,
+    /// Record batches currently buffered.
+    pub batches: i64,
+    /// Names of the indexes this memtable carries. An absent name is the whole
+    /// answer to "why is my fresh-tier search on that column brute-force".
+    pub indexes: Vec<String>,
+}
+
+impl From<lancedb::table::MemtableStats> for MemtableStats {
+    fn from(m: lancedb::table::MemtableStats) -> Self {
+        Self {
+            generation: m.generation as i64,
+            rows: m.rows as i64,
+            bytes: m.bytes as i64,
+            batches: m.batches as i64,
+            indexes: m.indexes,
+        }
+    }
+}
+
+/// Live state of one bucket. A table is N buckets on one node; flattening to a
+/// single number hides the one hot bucket that is usually why someone opened
+/// this endpoint.
+#[napi(object)]
+#[derive(Clone, Debug)]
+pub struct BucketStats {
+    /// The shard this bucket writes.
+    pub shard_id: String,
+    /// `"Active"` or `"Sealed"` (drop-table 2PC in flight).
+    pub status: String,
+    /// Epoch of the writer that currently owns the shard.
+    pub writer_epoch: i64,
+    /// Version of the shard manifest these numbers were read from.
+    pub manifest_version: i64,
+    /// The generation the active memtable will become.
+    pub current_generation: i64,
+    /// WAL position replay resumes from.
+    pub replay_after_wal_entry_position: i64,
+    /// Highest WAL position the writer has seen. The difference against
+    /// `replayAfterWalEntryPosition` is the WAL lag.
+    pub wal_entry_position_last_seen: i64,
+    /// Flushed L0 generations not yet merged into the base table.
+    pub generations: Vec<GenerationStats>,
+    /// Whether a pass owns this bucket's compaction latch right now. Says *a*
+    /// driver is running, not *whose*, and the latch is held from dispatch —
+    /// including while the pass queues for a pod-wide compactor permit. Read it
+    /// as "do not pile on", never as "mine is progressing".
+    pub compacting: bool,
+    /// Oldest first, active last. Absent for a `"Sealed"` bucket, whose
+    /// in-memory state is torn down.
+    pub memtables: Option<Vec<MemtableStats>>,
+}
+
+impl From<lancedb::table::BucketStats> for BucketStats {
+    fn from(b: lancedb::table::BucketStats) -> Self {
+        Self {
+            shard_id: b.shard_id,
+            status: b.status,
+            writer_epoch: b.writer_epoch as i64,
+            manifest_version: b.manifest_version as i64,
+            current_generation: b.current_generation as i64,
+            replay_after_wal_entry_position: b.replay_after_wal_entry_position as i64,
+            wal_entry_position_last_seen: b.wal_entry_position_last_seen as i64,
+            generations: b.generations.into_iter().map(Into::into).collect(),
+            compacting: b.compacting,
+            memtables: b
+                .memtables
+                .map(|ms| ms.into_iter().map(Into::into).collect()),
+        }
+    }
+}
+
+/// Live per-bucket LSM state, as returned by `Table#getLsmStats`.
+///
+/// Nothing here is derived: sums and differences (total L0 bytes, WAL lag) are
+/// the caller's to compute.
+#[napi(object)]
+#[derive(Clone, Debug)]
+pub struct LsmStats {
+    /// One entry per bucket backing this table.
+    pub buckets: Vec<BucketStats>,
+}
+
+impl From<lancedb::table::LsmStats> for LsmStats {
+    fn from(stats: lancedb::table::LsmStats) -> Self {
+        Self {
+            buckets: stats.buckets.into_iter().map(Into::into).collect(),
+        }
+    }
+}
+
 /// Statistics about a compaction operation.
 #[napi(object)]
 #[derive(Clone, Debug)]
@@ -1043,7 +1228,10 @@ impl From<lancedb::index::IndexStatistics> for IndexStatistics {
 
 #[napi(object)]
 pub struct TableStatistics {
-    /// The total number of bytes in the table
+    /// The total size, in bytes, of the table's data files, index files, and
+    /// overlay files
+    ///
+    /// Read from the manifest, so this excludes deletion files and manifests.
     pub total_bytes: i64,
 
     /// The number of rows in the table
@@ -1193,6 +1381,21 @@ pub struct AddColumnsResult {
     pub version: i64,
 }
 
+#[napi(object)]
+pub struct RefreshColumnResult {
+    pub rows_filled: i64,
+    pub version: i64,
+}
+
+impl From<lancedb::table::RefreshColumnResult> for RefreshColumnResult {
+    fn from(value: lancedb::table::RefreshColumnResult) -> Self {
+        Self {
+            rows_filled: value.rows_filled as i64,
+            version: value.version as i64,
+        }
+    }
+}
+
 impl From<lancedb::table::AddColumnsResult> for AddColumnsResult {
     fn from(value: lancedb::table::AddColumnsResult) -> Self {
         Self {

plugins/lancedb/.claude-plugin/plugin.json

@@ -1,21 +0,0 @@
-{
-  "name": "lancedb",
-  "description": "Write, review, debug, and document LanceDB pipelines in Python and TypeScript that work across local LanceDB OSS tables and remote LanceDB Enterprise/Cloud tables, with idiomatic query/search patterns and performance defaults for ingestion, indexing, filtering, and diagnostics.",
-  "version": "0.1.0",
-  "author": {
-    "name": "LanceDB"
-  },
-  "homepage": "https://www.lancedb.com",
-  "keywords": [
-    "lancedb",
-    "vector-search",
-    "full-text-search",
-    "hybrid-search",
-    "python",
-    "typescript",
-    "pipelines",
-    "ingestion",
-    "indexing",
-    "performance"
-  ]
-}

plugins/lancedb/.codex-plugin/plugin.json

@@ -1,33 +0,0 @@
-{
-  "name": "lancedb",
-  "version": "0.1.0",
-  "description": "Codex plugin for building LanceDB pipelines in Python and TypeScript.",
-  "author": {
-    "name": "LanceDB"
-  },
-  "keywords": [
-    "lancedb",
-    "vector-search",
-    "full-text-search",
-    "hybrid-search",
-    "python",
-    "typescript",
-    "pipelines"
-  ],
-  "skills": "./skills/",
-  "interface": {
-    "displayName": "LanceDB",
-    "shortDescription": "Build LanceDB pipelines in Python and TypeScript.",
-    "longDescription": "Write, review, debug, and document LanceDB pipelines in Python and TypeScript that work across local LanceDB OSS tables and remote LanceDB Enterprise/Cloud tables, with idiomatic query/search patterns and performance defaults for ingestion, indexing, filtering, and diagnostics.",
-    "developerName": "LanceDB",
-    "websiteURL": "https://www.lancedb.com",
-    "category": "Developer Tools",
-    "capabilities": [
-      "Developer Tools"
-    ],
-    "defaultPrompt": "Create a LanceDB table, embed sample text, and run a vector search.",
-    "composerIcon": "./assets/logo.png",
-    "logo": "./assets/logo.png",
-    "logoDark": "./assets/logo-dark.png"
-  }
-}

plugins/lancedb/skills/lancedb/SKILL.md

@@ -1,87 +0,0 @@
----
-name: lancedb
-description: Use when writing, reviewing, debugging, or documenting LanceDB pipelines in Python or TypeScript, especially code that should work across local LanceDB OSS tables and remote LanceDB Enterprise/Cloud tables. Helps avoid non-portable full-table materialization, choose idiomatic query/search patterns, apply LanceDB performance defaults for ingestion, indexing, filtering, and diagnostics, and resolve connections to the remote server for Enterprise-only operations such as jobs.
----
-
-# Building LanceDB Pipelines
-
-Use this skill to produce LanceDB pipelines that are portable between local and remote tables (for LanceDB Enterprise/Cloud) and idiomatic for the selected SDK.
-
-## LanceDB Table Modes
-
-LanceDB has two common execution modes:
-
-- **Local table**: embedded, open source, in-process LanceDB. The client opens data from a local path or object storage URI and executes queries in the application process.
-- **Remote table**: LanceDB Enterprise/Cloud table opened through a `db://...` URI. The data may be very large, commonly backed by object storage, and queried through a remote service.
-
-Do NOT assume local-only table helpers exist on remote tables. If the user asks for LanceDB Enterprise, Cloud, `db://...`, production remote access, or a remote table, focus on the remote table path: use `search()` / `query()`, keep reads bounded with `select()` and `limit()`, and avoid table-level full materialization APIs.
-
-## Workflow
-
-1. Identify the SDK: Python, TypeScript, or both.
-2. Identify the table mode: local/embedded OSS, remote Enterprise/Cloud, or portable across both. If the user says "LanceDB Enterprise", choose the remote table path. If the task involves jobs in any way (listing, inspecting, creating, or canceling jobs), it is always the remote path and requires a remote server connection — see "Connecting to the LanceDB remote server" below before doing anything else.
-3. Read the matching language branch before writing or changing code:
-   - Python patterns: `references/python/patterns.md`
-   - Python API quick reference: `references/python/api_reference.md`
-   - Python performance guidance: `references/python/performance.md`
-   - TypeScript patterns: `references/typescript/patterns.md`
-   - TypeScript API quick reference: `references/typescript/api_reference.md`
-   - TypeScript performance guidance: `references/typescript/performance.md`
-   - Column metadata authoring (both SDKs): `references/column_metadata.md`
-   - Branch operations (both SDKs): `references/branch_ops.md`
-   - Remote server connection resolution (jobs, raw REST): `references/remote_connect.md`
-   - Job operations REST API (list/describe/cancel/query_events): `references/remote_jobs.md`
-4. Start with `patterns.md` for the selected SDK. Read `api_reference.md` when choosing method names or return collectors. Read `performance.md` when the task involves ingestion, indexing, filtering, query tuning, diagnostics, or large datasets. Read `column_metadata.md` when the task is documenting, tagging, classifying, or grouping table columns (field descriptions, `lancedb:tag:*` tags, logical column families). Read `branch_ops.md` when the task involves branch lifecycle (list/create/delete), writing to a non-main branch, or verifying a change stayed off main. Read `remote_connect.md` when the task involves jobs or direct REST access to an Enterprise deployment, and `remote_jobs.md` for the job REST methods themselves (list, describe, cancel, query_events).
-5. For Python schemas, favor Pydantic models and validate records before writing. Use PyArrow schemas when Arrow-native, streaming, or highly dynamic data makes them materially better suited.
-6. Prefer `search()` or `query()` builders with explicit `select()` and `limit()` for reads.
-7. Avoid table-level full materialization in remote or portable code. This is the main local-vs-remote read pitfall.
-8. After a successful embedded OSS ingestion, call `table.optimize()`. Do not call it for Enterprise/Cloud; remote maintenance is automatic.
-9. For remote Enterprise/Cloud writes, never drop-then-reuse or `mode="overwrite"` the same table name — see "Enterprise: never drop-then-reuse the same table name" below. This is the main local-vs-remote write pitfall.
-10. If reviewing an existing file or repo, run `scripts/check_materialization.py` on the relevant paths and inspect each finding before editing.
-11. Cross-check unfamiliar or non-trivial API claims against the source tree instead of relying on memory.
-
-## Core Portability Rule
-
-Do not write code that assumes a local table API will exist on a remote table. Remote tables can be very large, so whole-table materialization helpers are intentionally unavailable or unsafe.
-
-This does **not** mean result conversion is forbidden. Bounded query/search result collection is normal:
-
-- Python: `table.search(...).select([...]).limit(10).to_pandas()`
-- TypeScript: `await table.search(...).select([...]).limit(10).toArray()`
-
-The unsafe pattern is table-level or unbounded collection, plus local-only dataset escape hatches in remote code:
-
-- Python: `table.to_pandas()`, `table.to_arrow()`, `table.to_polars()`; `table.to_lance()` is local/OSS-only dataset access, not materialization
-- TypeScript: `await table.toArrow()`, `await table.query().toArray()` without `limit()`
-
-## Enterprise: never drop-then-reuse the same table name
-
-LanceDB Enterprise/Cloud splits a **control plane** (DDL: create/drop/rename) from a **data plane** (query nodes that serve reads). Query nodes cache the resolved dataset for a table name for up to `table_cache_ttl` — **default 300 seconds (5 minutes)**. After you drop or overwrite a table, the control plane updates immediately but the data plane keeps serving the *old* dataset until that cache entry expires. During the window the two planes disagree.
-
-The failure this causes: you `drop_table("t")` then immediately `create_table("t", ...)` (or `create_table("t", ..., mode="overwrite")`). The DDL returns success, but every query against `t` returns **`500 Internal Server Error`** (the query node resolves the stale/deleted dataset), and a fresh `describe` may still show the *old* schema/version. It looks like your write silently failed; it didn't — the name is cached.
-
-**`mode="overwrite"` has the same problem** — it is a drop+create of the same name under the hood.
-
-Rules for portable Enterprise ingestion:
-
-1. **Never reuse a table name you just dropped/overwrote within the cache TTL.** Do not use `mode="overwrite"` to replace an existing Enterprise table in place.
-2. To (re)load data, **write to a fresh table name** (e.g. `<table>_v2`, or a run-stamped suffix). A brand-new name has no cached data-plane entry, so writes and reads work immediately.
-3. Before creating, `list_tables()` and **fail loudly if the name already exists** rather than overwriting — prompt for a new name.
-4. To land on a specific final name that is currently occupied by an old table: drop the old table, **wait out the TTL (~5 min), then `rename_table(fresh_name, final_name)`**. Renaming onto a name whose old dataset is still cached hits the same race, so the wait is mandatory. `rename_table` is a supported control-plane op.
-5. When you hand a table name back to a human, tell them which step still needs the propagation wait (usually: "the old `t` was dropped; run the rename in ~5 minutes").
-
-This is Enterprise/Cloud-specific. Local/OSS tables have no separate data plane, so `mode="overwrite"` and immediate same-name reuse are fine there.
-
-## Connecting to the LanceDB remote server
-
-LanceDB Enterprise/Cloud deployments are served by a server implementing the lance-namespace OpenAPI spec (<https://github.com/lance-format/lance-namespace/blob/main/docs/src/spec.yaml>). Every remote (`db://...`) connection talks to such a server, and some operations exist only there. In particular, **all operations around jobs (listing, inspecting, creating, or canceling jobs) run server-side** — there is no local/OSS equivalent. Before any job work, or any direct REST call to an Enterprise deployment, read `references/remote_connect.md` to resolve the base URL, credentials, and database header and to validate the connection. Then use the four job REST methods documented in `references/remote_jobs.md` (list, describe, cancel, query_events).
-
-## Script
-
-Run the scanner when reviewing or modifying an existing codebase:
-
-```bash
-python skills/lancedb/scripts/check_materialization.py path/to/file_or_dir
-```
-
-The script reports likely unsafe full-table materialization in Python and TypeScript. Treat results as review prompts, not automatic proof of a bug.

plugins/lancedb/skills/lancedb/agents/openai.yaml

@@ -1,6 +0,0 @@
-interface:
-  display_name: "LanceDB"
-  short_description: "Build LanceDB pipelines in Python and TypeScript"
-  default_prompt: "Use $lancedb to create a table, embed sample text, and run a vector search."
-  icon_small: "./assets/icon.png"
-  icon_large: "./assets/icon.png"

plugins/lancedb/skills/lancedb/references/branch_ops.md

@@ -1,182 +0,0 @@
-# Branch Operations
-
-Manage branches on a LanceDB table: list what exists, create new ones, delete stale ones, and direct read/write operations at a specific branch without touching main. Use for branch lifecycle tasks, experimental/isolated table versions, targeting an operation at a non-main branch, or confirming a mutation did not affect main.
-
-Works on local/OSS and remote Enterprise/Cloud tables, except merging a branch into main, which is Enterprise-only.
-
-## The branch model (important)
-
-Branches are isolated, writable lines of history forked from another branch (or a specific version). Writes on a branch never affect `main`.
-
-There is **no global "switch branch" state** — you never repoint the whole table at a branch. Instead, **operations are scoped by which table handle you use**:
-
-- The handle you got from `open_table(name)` / `openTable(name)` targets `main`.
-- `branches.create(...)` and `branches.checkout(...)` return a **new table handle scoped to that branch**. Every read/write on that handle (add, update, `update_field_metadata`, `create_index`, search, …) lands on the branch.
-- The original main handle is unaffected — keep it around to verify isolation.
-
-`branches.list()` returns only non-main branches. Main always exists and is not listed.
-
-## Python
-
-`table.branches` is a property returning the branch manager; `table.current_branch()` tells you what a handle is scoped to (`None` = main).
-
-```python
-table = db.open_table("products")            # scoped to main
-
-# list — dict of name -> metadata (parent_branch, parent_version, ...); {} = only main
-table.branches.list()
-
-# create: forks from main by default and returns a handle scoped to the new branch
-exp = table.branches.create("experiment-reindex")
-exp = table.branches.create("exp2", from_ref="main", from_version=None)  # optional fork point
-
-# checkout an existing branch -> branch-scoped handle
-wip = table.branches.checkout("wip-branch")
-# with version= it pins to that version (read-only detached view); omit to track latest, writable
-
-# operate on the branch simply by using its handle
-wip.update_field_metadata(
-    {"path": "category", "metadata": {"lancedb:description": "Product category label."}}
-)
-wip.create_scalar_index("category")
-
-# delete: removes only the branch pointer; main and row data remain intact
-table.branches.delete("stale-2024")
-
-# alternatively, open a branch handle directly from the connection
-wip = db.open_table("products", branch="wip-branch")
-
-exp.current_branch()    # "experiment-reindex"
-table.current_branch()  # None (main)
-```
-
-Async: same shape — `table.branches` returns `AsyncBranches`; `await table.branches.create(...)` etc.
-
-## TypeScript
-
-`table.branches()` is an **async method** returning the `Branches` manager; `table.currentBranch()` returns the scoped branch or `null` for main.
-
-```typescript
-const table = await db.openTable("products"); // scoped to main
-const branches = await table.branches();
-
-// list — Record<string, BranchContents>; {} = only main
-await branches.list();
-
-// create: forks from main by default, returns a Table scoped to the new branch
-const exp = await branches.create("experiment-reindex");
-const exp2 = await branches.create("exp2", "main" /* fromRef */, undefined /* fromVersion */);
-
-// checkout an existing branch -> branch-scoped Table
-const wip = await branches.checkout("wip-branch");
-// with a version arg it pins (read-only detached view); omit to track latest, writable
-
-// operate on the branch simply by using its handle
-await wip.updateFieldMetadata([
-  { path: "category", metadata: { "lancedb:description": "Product category label." } },
-]);
-await wip.createIndex("category");
-
-// delete: removes only the branch pointer; main and row data remain intact
-await branches.delete("stale-2024");
-
-// alternatively, open a branch handle directly from the connection
-const wip2 = await db.openTable("products", { branch: "wip-branch" });
-
-exp.currentBranch();   // "experiment-reindex"
-table.currentBranch(); // null (main)
-```
-
-## Verifying isolation
-
-After writing to a branch, confirm the change did NOT land on main by reading through both handles:
-
-```python
-wip = table.branches.checkout("wip-branch")
-wip.update_field_metadata({"path": "category", "metadata": {"lancedb:description": "..."}})
-
-assert b"lancedb:description" in (wip.schema.field("category").metadata or {})
-assert b"lancedb:description" not in (table.schema.field("category").metadata or {})  # main untouched
-```
-
-Two handles on the same branch see each other's writes (e.g. `table.branches.create("exp")` and `db.open_table(name, branch="exp")`); main stays isolated.
-
-## Merging a branch into main (Enterprise only)
-
-Merge is available through the SDKs (`table.branches.merge(...)`) on **Enterprise tables only** — it is not supported on Cloud or local/OSS tables, which raise `NotSupported`.
-
-`merge` takes the branch to merge **from** and a `dry_run` flag. Both the SDK method and the underlying REST endpoint **actually merge by default** (`dry_run=False`); pass `dry_run=True` to only preview. A rejected merge is **not an exception** — it returns a result with `status="rejected"` rather than raising, so inspect the return value. Use `branches.diff(from_branch)` to inspect a branch's pending diff without attempting a merge.
-
-```python
-exp = "experiment-reindex"
-
-# preview only — returns status="ready" if it would merge cleanly
-preview = table.branches.merge(exp, dry_run=True)
-
-# actually merge (default)
-result = table.branches.merge(exp)
-if result["status"] == "merged":
-    print("landed at", result["mainVersionAfter"])
-elif result["status"] == "rejected":
-    print(result["diff"]["mergeBlockers"])   # why it was refused
-
-# inspect a branch's pending diff without merging
-diff = table.branches.diff(exp)
-```
-
-Async: `await table.branches.merge(exp)`, `await table.branches.diff(exp)`.
-
-```typescript
-const branches = await table.branches();
-const exp = "experiment-reindex";
-
-// preview only (second arg is dryRun)
-const preview = await branches.merge(exp, true);
-
-// actually merge (default)
-const result = await branches.merge(exp);
-if (result.status === "merged") {
-  console.log("landed at", result.mainVersionAfter);
-} else if (result.status === "rejected") {
-  console.log(result.diff.mergeBlockers);
-}
-
-const diff = await branches.diff(exp);
-```
-
-The result is the wire JSON, containing `status` (`ready` on a passing dry run, `merged` on success, `rejected` when refused — also `notImplemented`/`unknown`), the branch `diff` (including `mergeBlockers` explaining any rejection), a `preview` of the columns that would be promoted, and — after a real merge — `mainVersionAfter`.
-
-### Merge preconditions
-
-Merge only **promotes newly added columns** onto main; it does not replay arbitrary commits. Practically, a branch is mergeable only if it has **exactly one commit since it was created, and that commit added a column**. The merge is rejected (`status: "rejected"`, with `mergeBlockers` set) if:
-
-- the branch was forked from another branch rather than directly from main
-- main has advanced since the branch was forked
-- the branch's rows changed since the fork (row counts must match main exactly)
-- the branch removed columns or changed a column's type/nullability
-- the branch added no columns (index-only changes are not merged)
-
-### Adding a column in a single commit
-
-Because the branch must contain just one column-adding commit, add the column with its values in one operation rather than add-then-backfill:
-
-1. **SQL transformation** — `add_columns` with a SQL expression computed from existing columns, so the column lands populated in one commit.
-2. **Precompute the values** — compute the column's values externally, then add the fully-populated column in a single operation (e.g. via `merge_insert`/`add_columns` with the data ready).
-3. **Lance-format-level data evolution (pylance)** — use Lance's data evolution with backfill, documented at <https://lance.org/guide/data_evolution/#with-data-backfill>.
-
-## Quick reference
-
-| Goal | Python | TypeScript |
-|------|--------|------------|
-| List branches (non-main) | `table.branches.list()` | `await (await table.branches()).list()` |
-| Create branch (off main) | `table.branches.create(name)` → branch handle | `await branches.create(name)` → branch `Table` |
-| Create from a fork point | `table.branches.create(name, from_ref=..., from_version=...)` | `await branches.create(name, fromRef, fromVersion)` |
-| Get a branch handle | `table.branches.checkout(name)` or `db.open_table(t, branch=name)` | `await branches.checkout(name)` or `await db.openTable(t, { branch: name })` |
-| Pin to a branch version (read-only) | `table.branches.checkout(name, version=v)` | `await branches.checkout(name, v)` |
-| Delete branch | `table.branches.delete(name)` | `await branches.delete(name)` |
-| Which branch is this handle on? | `table.current_branch()` (`None` = main) | `table.currentBranch()` (`null` = main) |
-| Target main | use the original (non-branch) handle | use the original (non-branch) handle |
-| Merge branch into main (Enterprise only) | `table.branches.merge(from_branch, dry_run=False)` | `await branches.merge(fromBranch, dryRun)` |
-| Preview a branch's pending diff (Enterprise only) | `table.branches.diff(from_branch)` | `await branches.diff(fromBranch)` |
-
-Branch names must be non-empty; empty names raise a validation error.

plugins/lancedb/skills/lancedb/references/column_metadata.md

@@ -1,183 +0,0 @@
-# Column Metadata Authoring
-
-Write column-level descriptions, tags, and logical groupings onto a LanceDB table's schema. Use this when the user wants to document, annotate, tag, or classify what their table columns ARE (embeddings vs labels vs eval metrics, model provenance, version families, etc.).
-
-Works on local/OSS and remote Enterprise/Cloud tables alike — read the schema through the table handle, write through `update_field_metadata` (Python) / `updateFieldMetadata` (TypeScript).
-
-## Metadata key conventions
-
-All metadata uses namespaced keys:
-
-| Key | Purpose | Example value |
-|-----|---------|---------------|
-| `lancedb:description` | Human-readable explanation of what the column contains | `"CLIP ViT-L/14 image embedding, L2-normalized (768-dim)"` |
-| `lancedb:tag:<name>` | Flexible key-value tag; the suffix names the tag category | `lancedb:tag:field_type: "embedding"`, `lancedb:tag:model: "clip"`, `lancedb:tag:project_id: "foo"` |
-| `lancedb:logical-column` | Logical group/family this column belongs to | `"clip_features"` |
-
-Tags are open-ended — use whatever key suffix and value make sense given the user's intent. The tag suffix should describe *what is being classified* (e.g., `field_type`, `model`, `project_id`) and the value describes *how*. Multiple tags on the same column are fine — each is a separate key. All values are strings.
-
-## Step 1: Read the schema and existing metadata
-
-Read existing metadata before writing, to avoid redundant updates.
-
-Python — `table.schema` (sync property; async: `await table.schema()`) returns a `pyarrow.Schema`. **Arrow field metadata is bytes-keyed in Python**:
-
-```python
-schema = table.schema
-for field in schema:
-    meta = field.metadata or {}  # dict[bytes, bytes], e.g. {b"lancedb:description": b"..."}
-    print(field.name, field.type, field.nullable, meta)
-```
-
-TypeScript — `await table.schema()` returns an Arrow `Schema`; field metadata is a `Map<string, string>`:
-
-```typescript
-const schema = await table.schema();
-for (const field of schema.fields) {
-  console.log(field.name, field.type, field.nullable, field.metadata); // Map
-  // field.metadata.get("lancedb:description")
-}
-```
-
-For struct/nested fields, recurse into the field's children and address them as dot-paths (e.g., `parent.child`).
-
-If the user hasn't specified which columns to update, work with all columns.
-
-## Step 2: Generate metadata
-
-Decide what to generate based on the user's request.
-
-### Descriptions (`lancedb:description`)
-
-Base descriptions on:
-- The column name and Arrow type (e.g., `FixedSizeList` of floats → likely an embedding)
-- User-supplied context (upstream pipeline, sample values, domain knowledge)
-- Name patterns: `_embedding`/`_vec`/`_embed` → vector; `_label`/`_class` → label; `_score`/`_eval`/`_metric` → evaluation metric
-
-Be specific and concise. Good: `"Sentence-BERT embedding of the query text (768-dim)."` Not: `"An embedding column."`
-
-### Tags (`lancedb:tag:<name>`)
-
-Choose tag key names that match what the user asked to annotate. Common patterns:
-
-- Semantic field type → `lancedb:tag:field_type: "embedding"` / `"text"` / `"image"` / `"label"` / `"eval"` / `"id"` / `"metadata"`
-- Model or source → `lancedb:tag:model: "clip"` / `"bert"` / `"vit"`
-- Project affiliation → `lancedb:tag:project_id: "<name>"`
-- Version → `lancedb:tag:version: "v3"` (and `lancedb:tag:latest: "true"` for the newest)
-
-Use Arrow type as a hint: `FixedSizeList` + float → embedding; `Utf8`/`LargeUtf8` → text; `Binary` → image or blob.
-
-### Logical groupings (`lancedb:logical-column`)
-
-Look for naming patterns across columns:
-- `clip_v1`, `clip_v2`, `clip_v3` → logical column `"clip"`, latest is `v3`
-- `text_embed_20240101`, `text_embed_20240601` → logical column `"text_embed"`, latest is the most recent date suffix
-
-Write `lancedb:logical-column` on all members of a group. Mark the newest with `lancedb:tag:latest: "true"` (in addition to its version tag).
-
-## Step 3: Write the metadata
-
-Each update names a field by dot-path and carries a metadata map. Semantics (identical in both SDKs):
-
-- **Merge by default** (`replace` omitted/false) — preserves existing metadata the user didn't ask to change
-- `replace: true` swaps the field's entire metadata map — only if the user explicitly asks to overwrite
-- A value of `None`/`null` deletes that specific key
-- Batch all field updates into a single call when possible
-- Returns the new table version
-
-Python (sync and async take one dict per field, as varargs):
-
-```python
-res = table.update_field_metadata(
-    {
-        "path": "clip_v3",
-        "metadata": {
-            "lancedb:description": "CLIP ViT-L/14 image embedding, L2-normalized (1024-dim).",
-            "lancedb:tag:field_type": "embedding",
-            "lancedb:tag:model": "clip",
-            "lancedb:tag:version": "v3",
-            "lancedb:tag:latest": "true",
-            "lancedb:logical-column": "clip",
-        },
-    },
-    {
-        "path": "clip_v2",
-        "metadata": {
-            "lancedb:description": "CLIP ViT-B/32 image embedding (768-dim), superseded by v3.",
-            "lancedb:tag:field_type": "embedding",
-            "lancedb:tag:model": "clip",
-            "lancedb:tag:version": "v2",
-            "lancedb:logical-column": "clip",
-        },
-    },
-)
-print(res.version)  # new table version
-
-# merge semantics: add a key, delete one via None, keep the rest
-table.update_field_metadata(
-    {"path": "clip_v2", "metadata": {"lancedb:tag:archived": "true", "lancedb:tag:latest": None}}
-)
-```
-
-(`replace_field_metadata` is deprecated — use `update_field_metadata`.)
-
-TypeScript (takes an array of `FieldMetadataUpdate`):
-
-```typescript
-const res = await table.updateFieldMetadata([
-  {
-    path: "clip_v3",
-    metadata: {
-      "lancedb:description": "CLIP ViT-L/14 image embedding, L2-normalized (1024-dim).",
-      "lancedb:tag:field_type": "embedding",
-      "lancedb:tag:model": "clip",
-      "lancedb:tag:version": "v3",
-      "lancedb:tag:latest": "true",
-      "lancedb:logical-column": "clip",
-    },
-  },
-  {
-    path: "clip_v2",
-    metadata: {
-      "lancedb:description": "CLIP ViT-B/32 image embedding (768-dim), superseded by v3.",
-      "lancedb:tag:field_type": "embedding",
-      "lancedb:tag:model": "clip",
-      "lancedb:tag:version": "v2",
-      "lancedb:logical-column": "clip",
-    },
-  },
-]);
-console.log(res.version); // new table version
-
-// merge semantics: add a key, delete one via null, keep the rest
-await table.updateFieldMetadata([
-  { path: "clip_v2", metadata: { "lancedb:tag:archived": "true", "lancedb:tag:latest": null } },
-]);
-```
-
-## Step 4: Confirm
-
-Report back:
-- Which columns were updated and what was written
-- The new table version number (from the result)
-- Any columns skipped (e.g., already had up-to-date metadata)
-
-## Quick examples
-
-**"Write descriptions for all columns in the `product_embeddings` table"**
-1. Read `table.schema` → all fields + existing metadata
-2. Generate a `lancedb:description` for each column based on name + type
-3. One `update_field_metadata` call with all descriptions
-4. Report
-
-**"Tag the columns in `model_outputs` with their field type and model"**
-1. Read the schema
-2. For each field, classify by name + Arrow type → set `lancedb:tag:field_type` and `lancedb:tag:model` where applicable
-3. Write in one batched call
-4. Report
-
-**"Group the feature columns in `training_features` into logical families and mark the latest version"**
-1. Read the schema
-2. Find version patterns → assign `lancedb:logical-column` and `lancedb:tag:version`; mark newest with `lancedb:tag:latest: "true"`
-3. Write in one batched call
-4. Show the grouping

plugins/lancedb/skills/lancedb/references/python/api_reference.md

@@ -1,138 +0,0 @@
-# Python API Reference
-
-Quick method reference for Python LanceDB code. Cross-check source for non-trivial claims.
-
-## Connect
-
-If you're connecting to a remote database, use this:
-```python
-import lancedb
-
-db = lancedb.connect("db://my-db", api_key=api_key, host_override=host_override) # remote
-```
-(values may be found in LANCEDB_API_KEY and LANCEDB_HOST_OVERRIDE, either in env vars or a .env file)
-
-If you're connecting to a local table using OSS LanceDB, use this:
-```python
-db = lancedb.connect("./camelot-db") # local/OSS
-```
-If you're not sure which, or if you can't find the api_key or host_override params, ask the user.
-
-**Place the local database directory next to the script/entrypoint that opens it** (i.e. resolve the path relative to the script, `Path(__file__).parent / "camelot-db"`), not buried under a shared `data/` folder. The Lance dataset is the database, not a data file — keeping it beside its code makes ownership obvious and paths stable regardless of the working directory the script is launched from.
-
-**Do not name the directory `lancedb`** (e.g. `./lancedb`, `./data/lancedb`). It collides with the imported `lancedb` package name, which is confusing to read and easy to shadow in scripts. Give it a name derived from the repo or dataset with a clear prefix/suffix — for example `./<dataset>-db`, `./<repo>_lancedb`, or `./vectordb`.
-
-Async:
-
-```python
-db = await lancedb.connect_async("./camelot-db")
-```
-
-## Table Reads
-
-| Task | Preferred API |
-| --- | --- |
-| Vector search | `table.search(query_vector).limit(k)` |
-| Full scan with filters/projection (sync) | `table.search().where(...).select(...).limit(...)` |
-| Full scan with filters/projection (async) | `table.query().where(...).select(...).limit(...)` |
-| Filter | `.where("col > 10")` |
-| Projection | `.select(["id", "text"])` |
-| Bound result count | `.limit(20)` |
-| Collect bounded result as Python objects (default, no extra deps) | `.to_list()` on query/search result |
-| Collect bounded result as Arrow (default, `pyarrow` always available) | `.to_arrow()` on query/search result |
-| Collect bounded result as pandas (only if project uses pandas) | `.to_pandas()` on query/search result |
-| Collect bounded result as Polars (only if project uses polars) | `.to_polars()` on query/search result |
-
-## Sync vs Async Scan API
-
-The plain-scan entry point differs between the sync and async clients. **Verified against `lancedb` 0.34.0** — re-check if the pinned version changes:
-
-- **Sync** (`lancedb.connect(...)`): the table has **no `.query()` method**. Use `.search()` with no argument for a plain scan; it returns a query builder that supports `.where()`, `.select()`, `.limit()`, and the `.to_list()` / `.to_arrow()` / `.to_pandas()` / `.to_polars()` collectors.
-  ```python
-  rows = table.search().where("status = 'ready'").select(["id", "text"]).limit(20).to_list()
-  ```
-- **Async** (`lancedb.connect_async(...)`): the table has **both** `.query()` and `.search()`. Use `.query()` for a plain scan.
-  ```python
-  rows = await async_table.query().where("status = 'ready'").select(["id", "text"]).limit(20).to_list()
-  ```
-
-Do not call `table.query()` on a sync table — it raises `AttributeError`.
-
-## Local vs Remote Table Methods
-
-| API | Local table | Remote table | Agent guidance |
-| --- | --- | --- | --- |
-| `table.search(...)` | Yes | Yes | Preferred read path (sync + async) |
-| `table.query()` | Async only | Async only | Sync scan path is `table.search()`; `.query()` is the async scan builder |
-| `table.to_pandas()` | Yes | No / unsafe for portability | Avoid in portable code |
-| `table.to_arrow()` | Yes | No / unsafe for portability | Avoid in portable code |
-| `table.to_polars()` | Yes | No / unsafe for portability | Avoid in portable code |
-| `table.to_lance()` | Yes | No | Local/OSS escape hatch only |
-
-## Indexes
-
-Use `create_index(...)` for vector indexes and modern index configs. Use scalar indexes for filtered or merge keys.
-
-Common calls:
-
-```python
-table.create_index("vector")
-table.create_scalar_index("status")
-table.create_fts_index("text")
-```
-
-Check source docs before specifying advanced index config names or parameters.
-
-## Filtering And Recall Knobs
-
-```python
-table.search(query_vector).where("status = 'ready'")  # pre-filter by default
-table.search(query_vector).where("status = 'ready'", prefilter=False)
-table.search(query_vector).limit(10).refine_factor(20)
-table.search(query_vector).limit(10).nprobes(50)
-```
-
-Use post-filtering only when fewer than `limit` results are acceptable.
-
-## Diagnostics
-
-```python
-print(table.search(query_vector).where("year > 2000").limit(10).analyze_plan())
-print(table.index_stats("vector_idx"))
-```
-
-Use these before changing indexes or search tuning.
-
-## Column (Field) Metadata
-
-```python
-schema = table.schema                       # sync property; async: await table.schema()
-meta = schema.field("category").metadata    # dict[bytes, bytes] — Arrow metadata is bytes-keyed
-res = table.update_field_metadata(          # varargs: one dict per field; works local + remote
-    {"path": "category", "metadata": {"lancedb:description": "...", "lancedb:tag:field_type": "label"}}
-)
-res.version  # new table version
-```
-
-Merges by default; a `None` value deletes that key; `"replace": True` swaps the whole map. Nested fields use dot-paths (`"a.b.c"`). `replace_field_metadata` is deprecated. See `references/column_metadata.md` for key conventions (`lancedb:description`, `lancedb:tag:<name>`, `lancedb:logical-column`) and the authoring workflow.
-
-## Branches
-
-```python
-table.branches.list()                          # non-main branches; {} = only main
-exp = table.branches.create("exp")             # fork off main -> handle scoped to the branch
-wip = table.branches.checkout("wip")           # existing branch -> scoped handle (version= pins read-only)
-wip = db.open_table("t", branch="wip")         # or open scoped directly
-table.branches.delete("stale")                 # removes only the branch pointer
-table.current_branch()                         # None = main
-```
-
-There is no global switch — scoping is per table handle: any read/write on a branch handle lands on that branch; the original handle keeps targeting main. See `references/branch_ops.md` for the model and isolation checks.
-
-## Maintenance
-
-```python
-table.optimize()
-```
-
-Call this after every successful local/OSS ingestion. It handles compaction, cleanup of old versions according to retention, and index optimization. Do not add this for LanceDB Enterprise/Cloud remote tables; Enterprise handles compaction and cleanup automatically from cluster configuration.

plugins/lancedb/skills/lancedb/references/python/patterns.md

@@ -1,173 +0,0 @@
-# Python Patterns
-
-Use these patterns when writing Python code with `lancedb`.
-
-## Before Writing Code
-
-Choose the output type from what the project actually depends on. **Do not assume `pandas` or `polars` is installed** — they are heavy dependencies that many LanceDB projects do not use. `pyarrow`, by contrast, ships as a LanceDB dependency and is always available, so it is a safe default to lean on.
-
-Default output (after applying `select()` and `limit()`):
-
-- **Python objects**: `.to_list()` — a list of dicts, no extra dependencies. Prefer this for scripts, examples, and agent-generated code unless there is a reason to do otherwise.
-- **PyArrow**: `.to_arrow()` — a `pyarrow.Table`, when the surrounding code is Arrow-native or you need columnar/zero-copy handoff.
-
-Only reach for a DataFrame when the project *already* declares that dependency:
-
-- Pandas projects (pandas in `pyproject.toml`/requirements): `.to_pandas()`.
-- Polars projects (polars declared): `.to_polars()`.
-
-If unsure, check the dependency manifest or the imports in surrounding files. When in doubt, use `.to_list()` or `.to_arrow()`.
-
-## Schema Design and Validation
-
-Favor `LanceModel` and Pydantic validation for Python schemas. They keep field
-types readable, validate source records before a write, and map directly to a
-LanceDB schema. Use `Vector(dimension)` for fixed-size vectors:
-
-```python
-from lancedb.pydantic import LanceModel, Vector
-
-class Document(LanceModel):
-    id: int
-    text: str
-    vector: Vector(384, nullable=False)
-
-rows = [Document.model_validate(row) for row in source_rows]
-table = db.create_table("documents", schema=Document)
-table.add(rows)
-```
-
-Use PyArrow schemas instead when the pipeline is already Arrow-native, needs
-record-batch streaming, or has runtime schema requirements that would make a
-Pydantic model harder to understand. Declare Pydantic as a direct project
-dependency when application code imports it, even if LanceDB also depends on it.
-
-## Recommended Patterns
-
-### Bounded search or query
-
-Use this for application reads, examples, notebooks, and agent-generated scripts:
-
-```python
-results = (
-    table.search(query_vector)
-    .where("status = 'ready'")
-    .select(["id", "text"])
-    .limit(20)
-    .to_list()  # or .to_arrow(); .to_pandas()/.to_polars() only if the project uses them
-)
-```
-
-Why: `search()` works across local and remote tables and on both the sync and async clients. `select()` avoids fetching unused columns. `limit()` prevents accidental full-table reads. `.to_list()` and `.to_arrow()` avoid assuming pandas/polars is installed (see "Before Writing Code").
-
-For a **plain scan** (no query vector), the entry point differs by client:
-
-```python
-# Sync client: no .query() method — use .search() with no argument.
-rows = table.search().where("status = 'ready'").select(["id", "text"]).limit(20).to_list()
-
-# Async client: use .query().
-rows = await async_table.query().where("status = 'ready'").select(["id", "text"]).limit(20).to_list()
-```
-
-`table.query()` on a sync table raises `AttributeError` (verified on `lancedb` 0.34.0). See the "Sync vs Async Scan API" section in `api_reference.md`.
-
-### Bounded query result conversion
-
-It is fine to collect bounded query/search results:
-
-```python
-arrow_table = table.search().select(["id"]).limit(100).to_arrow()  # sync plain scan
-rows = table.search(query_vector).limit(10).to_list()
-df = table.search(query_vector).limit(10).to_pandas()  # only if pandas is a project dep
-```
-
-### Local-only Lance dataset API
-
-`table.to_lance()` does not itself materialize the full dataset. It returns the underlying `lance.LanceDataset`, making the table accessible through the PyLance dataset API. Use it when the task is explicitly local/OSS and needs Lance dataset methods not exposed by LanceDB:
-
-```python
-# Local/OSS only: RemoteTable does not expose table.to_lance().
-ds = table.to_lance()
-for batch in ds.to_batches(columns=["id", "text"], batch_size=10_000):
-    process(batch)
-```
-
-### Async Python
-
-Keep the same shape and bound the result before collecting:
-
-```python
-results = await (
-    async_table.query()
-    .where("status = 'ready'")
-    .select(["id", "text"])
-    .limit(20)
-    .to_list()  # or .to_arrow()
-)
-```
-
-## Anti-Patterns
-
-**Avoid the following anti-patterns in your code.**
-
-### Table-level full materialization
-
-Avoid whole-table collectors in portable or large-table code:
-
-```python
-df = table.to_pandas()
-arrow_table = table.to_arrow()
-polars_df = table.to_polars()
-```
-
-Why: local tables expose these whole-table collectors, but remote tables intentionally do not — a remote production table can be far larger than a local development table, so it is easy to accidentally pull the entire table into memory.
-
-`table.to_lance()` is different: it is not a full materialization call, but it is still local/OSS-only and should not appear in code meant to run against remote Enterprise tables.
-
-### Unbounded result collection
-
-Avoid query/search collection without a meaningful limit:
-
-```python
-rows = table.search().to_list()               # unbounded plain scan
-rows = table.search(query_vector).to_list()   # unbounded vector search
-```
-
-Prefer `select(...).limit(...)` before collecting; for large reads, stream in batches instead.
-
-### Per-row writes
-
-Avoid loops that write one row per call:
-
-```python
-for row in rows:
-    table.add([row])  # one commit + fragment per row
-```
-
-Each `add()` creates a new version and fragment. Pass the whole batch in a single call, or chunk very large inputs:
-
-```python
-table.add(rows)  # single commit
-# for very large inputs, add batches of several thousand rows
-```
-
-After the final successful write to an embedded OSS table, call
-`table.optimize()`. Skip this for Enterprise/Cloud tables because their
-maintenance is automatic.
-
-### Drop-then-reuse the same table name (Enterprise/Cloud)
-
-Avoid dropping or overwriting a remote table and then reusing that name right away:
-
-```python
-db.drop_table("my_table")
-table = db.create_table("my_table", data=rows)          # reads 500 for ~5 min
-table = db.create_table("my_table", data=rows, mode="overwrite")  # same problem
-```
-
-Why: Enterprise/Cloud splits DDL (control plane) from query serving (data plane). The data plane caches the dataset behind a table name for up to `table_cache_ttl` (default 300s / 5 min), so after a drop/overwrite the DDL succeeds but queries against the reused name return `500 Internal Server Error` until the cache expires — and a fresh `describe` may still show the old schema. Instead, write to a **fresh name**, use `list_tables()` and fail if it already exists, then `rename_table(fresh, final)` onto the final name only after the old table's drop has propagated (~5 min). See the "Enterprise: never drop-then-reuse the same table name" section in `SKILL.md`. Local/OSS tables have no separate data plane — overwrite freely there.
-
-### Guessing performance fixes
-
-Avoid changing `nprobes`, `refine_factor`, or index types before checking the query plan and index stats. Diagnose first, then tune one knob at a time.

plugins/lancedb/skills/lancedb/references/python/performance.md

@@ -1,131 +0,0 @@
-# Python Performance Guidance
-
-Use this when writing Python code that ingests data, queries large tables, builds indexes, or investigates latency.
-
-## Ingestion
-
-### Recommended: validate schemas and records with Pydantic
-
-Favor `LanceModel` for readable Python schema definitions and validate source
-records before writing. Use PyArrow directly for Arrow-native or streaming
-pipelines where it is the clearer representation.
-
-```python
-from lancedb.pydantic import LanceModel, Vector
-
-class Document(LanceModel):
-    id: int
-    text: str
-    vector: Vector(384, nullable=False)
-
-rows = [Document.model_validate(row) for row in source_rows]
-table = db.create_table("documents", schema=Document)
-table.add(rows)
-```
-
-### Recommended: bulk ingestion for materialized data
-
-```python
-table.add(arrow_table)
-table.add(df)
-table.add(pa.dataset("data/", format="parquet"))
-```
-
-For very large initial loads, create the table empty first, then call `add(...)`. Passing data directly to `create_table(name, data)` can skip the auto-parallel write path.
-
-### Recommended: iterator ingestion for generated or streamed data
-
-```python
-def batches():
-    for raw in source:
-        vectors = model.encode(raw["text"])
-        yield pa.RecordBatch.from_pydict({**raw, "vector": vectors})
-
-table.add(batches())
-```
-
-Use chunks of several thousand rows or more when practical. Tiny batches and per-row writes create many small fragments.
-
-### Anti-pattern: per-row `add()`
-
-```python
-for row in rows:
-    table.add([row])
-```
-
-Each call creates a version and fragment. This slows ingestion and later queries.
-
-## Indexing
-
-- Build a vector index once brute-force vector search becomes too slow. As a rule of thumb, local brute force is fine below roughly 100K vectors; beyond that, build an index.
-- Use `IVF_PQ` as the general-purpose default. Enterprise builds this automatically.
-- Use scalar indexes for filtered columns and merge/upsert keys.
-- Use `BTREE` for mostly distinct numeric/string/temporal columns, `BITMAP` for booleans and low-cardinality columns, and `LABEL_LIST` for list membership queries.
-- Keep full-text defaults unless phrase queries require position data.
-
-## Querying
-
-Always be explicit:
-
-```python
-table.search(query_vector).select(["id", "title"]).limit(20)
-```
-
-- `select()` reduces bytes read and transferred.
-- `limit()` prevents accidental full-table materialization.
-- Pre-filtering is the default and guarantees returned rows satisfy the predicate.
-- Use post-filtering only when fewer than `limit` results are acceptable.
-
-## Recall Tuning
-
-Tune one knob at a time:
-
-- Quantized indexes: raise `refine_factor` to rescore more candidates on full vectors.
-- HNSW-backed indexes: raise `ef`; start around `1.5 * k`, increase toward `10 * k` if recall is short.
-- IVF candidate breadth: `nprobes` is auto-tuned; override only when a selective pre-filter leaves too few neighbors.
-
-## Maintenance
-
-After every successful embedded OSS/local ingestion, call `table.optimize()`.
-Do not add this to LanceDB Enterprise/Cloud remote table code; remote compaction
-and cleanup are handled automatically based on the Enterprise cluster
-configuration.
-
-Why local maintenance is needed:
-
-- Frequent writes can create many small fragments. Queries then need to scan across more files, which can increase latency.
-- Updates, deletes, and appends create new table versions. Old versions are retained for time travel and rollback, which can grow disk usage.
-- Indexes may have newly added rows that are not yet fully optimized into the index structure.
-
-For local/OSS tables, run `optimize()` after the final successful ingestion
-write. Also run it after later batches of update/delete operations or on a
-regular maintenance schedule:
-
-```python
-table.optimize()
-```
-
-If the user wants more aggressive local disk cleanup, pass a shorter cleanup retention window:
-
-```python
-from datetime import timedelta
-
-table.optimize(cleanup_older_than=timedelta(days=1))
-```
-
-Do not use very short cleanup windows when the application depends on time travel, rollback, or old versions.
-
-## Diagnostics
-
-Before changing code or indexes, inspect:
-
-```python
-print(table.search(query_vector).where("year > 2000").limit(10).analyze_plan())
-print(table.index_stats("vector_idx"))
-```
-
-Look for high scan bytes, missing indexes, fragmented data, and unindexed rows.
-
-## Python Multiprocessing
-
-When using multiprocessing, use `spawn` rather than `fork`. LanceDB is multi-threaded internally, and `fork` plus a multi-threaded process is unsafe.

plugins/lancedb/skills/lancedb/references/remote_connect.md

@@ -1,45 +0,0 @@
-# Connecting to a LanceDB remote server
-
-LanceDB Enterprise/Cloud deployments are served by a server implementing the
-lance-namespace OpenAPI spec
-(<https://github.com/lance-format/lance-namespace/blob/main/docs/src/spec.yaml>).
-Every remote (`db://...`) connection talks to such a server, and some operations
-exist only there. In particular, all operations around jobs (listing, inspecting,
-creating, or canceling jobs) run server-side — there is no local/OSS equivalent, so
-resolve a server connection before attempting any job work. The job REST methods
-themselves are documented in `references/remote_jobs.md`.
-
-Every request needs two things:
-
-1. **Base URL** — the server endpoint
-2. **Credentials** — an API key (`x-api-key` header over REST), and usually a database name (`x-lancedb-database` header)
-
-## Resolution steps
-
-1. If the user already gave a URL and API key (or said which environment they're working against), use that.
-2. Otherwise, look for credentials already available in the environment:
-   - Env vars like `LANCEDB_URI` / `LANCEDB_HOST` / `LANCEDB_API_KEY`
-   - A server endpoint already running or port-forwarded locally (the REST default port is 2333, i.e. `http://localhost:2333`)
-3. If you didn't find both pieces, ask the user directly: **"What's your LanceDB endpoint's URL, and what's your API key?"** Also ask which database to use if it isn't obvious. Don't guess or probe further — the user knows their deployment.
-
-## Validating the connection
-
-Make a cheap authenticated request and check the status before starting real work:
-
-```bash
-curl -s -w "\n%{http_code}" "{base_url}/v1/table/?limit=1" \
-  -H "x-api-key: <key>" \
-  -H "x-lancedb-database: <database>"
-```
-
-- `200` — connection, key, and database header all good
-- `401` — API key missing or wrong
-- `400` mentioning a database header — this deployment expects `x-lancedb-database`
-
-## Non-REST equivalents
-
-The same credentials work through the SDKs and CLI:
-
-- Python SDK: `lancedb.connect("db://<database>", api_key="<key>", host_override="<base_url>")`
-- TypeScript SDK: `await lancedb.connect("db://<database>", { apiKey: "<key>", hostOverride: "<base_url>" })`
-- `lancedb` CLI: a `[profiles.<name>]` entry in `~/.lancedb/config.toml` with `http_server_url`, `api_key`, `database`

plugins/lancedb/skills/lancedb/references/remote_jobs.md

@@ -1,151 +0,0 @@
-# Job operations over the LanceDB remote server REST API
-
-Jobs are server-side background operations on LanceDB Enterprise/Cloud — index builds,
-column backfills, materialized view refreshes, and similar async work. Endpoints that
-trigger async work (e.g. the column backfill or materialized view refresh endpoints)
-return a `job_id`; these four methods are how you track and manage those jobs.
-
-Resolve the connection first — see `references/remote_connect.md`. All four methods
-are **POST** requests under `{base_url}/v1/jobs/` with JSON bodies, and take the usual
-`x-api-key` / `x-lancedb-database` headers. If every job call returns `501`, job APIs
-are disabled on that deployment (the server has no job registry configured) — report
-that rather than retrying.
-
-## 1. List jobs — `POST /v1/jobs/list`
-
-The body is optional; an empty body lists everything. All fields are filters:
-
-```json
-{
-  "limit": 100,
-  "table_name": "my_table",
-  "job_type": "...",
-  "job_subtype": "...",
-  "state": "...",
-  "page_token": "..."
-}
-```
-
-```bash
-curl -s -X POST "{base_url}/v1/jobs/list" \
-  -H "x-api-key: <key>" -H "x-lancedb-database: <database>" \
-  -H "content-type: application/json" \
-  -d '{"table_name": "my_table"}'
-```
-
-Response:
-
-```json
-{
-  "jobs": [
-    {
-      "job_id": "...",
-      "table": "my_table",
-      "job_type": "...",
-      "job_subtype": "...",
-      "state": "done",
-      "created_at_millis": 1720000000000
-    }
-  ],
-  "page_token": "..."
-}
-```
-
-A `page_token` in the response means there are more results — pass it back in the next
-request to continue. Note list rows use a lowercase `state` string, while describe uses
-an uppercase `job_state`.
-
-## 2. Describe a job — `POST /v1/jobs/describe`
-
-Body: `{"job_id": "<id>"}`. Returns full detail for one job:
-
-```json
-{
-  "job_id": "...",
-  "job_type": "...",
-  "job_subtype": "...",
-  "job_state": "IN_PROGRESS",
-  "creation_ms": 1720000000000,
-  "spec": {},
-  "status": {}
-}
-```
-
-`job_state` is one of `IN_PROGRESS`, `CANCELLED`, `FAILED`, `DONE`. `spec` and `status`
-are job-type-specific JSON objects (the job's input specification and its current
-progress/status). Returns `404` for an unknown job id.
-
-## 3. Cancel a job — `POST /v1/jobs/cancel`
-
-Body: `{"job_id": "<id>"}`; response echoes `{"job_id": "<id>"}`. Cancellation is a
-service-level operation requiring the same administrative authorization as the
-`/admin` routes — a database-scoped API key that can list and describe jobs may still
-get a permission error here. Other errors: `404` unknown job, `409` state conflict
-(e.g. already in a terminal state), `429` too much write contention (safe to retry).
-
-## 4. Query job event history — `POST /v1/jobs/query_events`
-
-Returns the event history (state transitions, progress updates) for one or more jobs.
-Body: `{"job_id": "<id>"}` for one job, or `{"job_ids": ["<id>", ...]}` for a batch.
-Optional fields: `limit` (max event rows), `limit_per_job` (per job in a batch query),
-and `filter` — a SQL-like expression over the columns `state`, `updated_by`,
-`owner_component`, and `claim_entity`. (`full_text_search` is reserved and currently
-rejected as not implemented.)
-
-The response is **not JSON** — it is an Arrow IPC stream
-(`content-type: application/vnd.apache.arrow.stream`). Decode it, e.g. in Python:
-
-```python
-import pyarrow.ipc
-import requests
-
-resp = requests.post(
-    f"{base_url}/v1/jobs/query_events",
-    headers={"x-api-key": key, "x-lancedb-database": database},
-    json={"job_id": job_id},
-)
-resp.raise_for_status()
-events = pyarrow.ipc.open_stream(resp.content).read_all()
-```
-
-## Feature engineering (Geneva) jobs
-
-Feature engineering jobs — UDF column backfills and materialized view refreshes run
-through Geneva — are tracked **separately** from the `/v1/jobs` registry above. Their
-records live in a `geneva_jobs` table inside the database itself (in the `__system`
-namespace), and you access them through a Python `geneva` connection rather than the
-REST endpoints above:
-
-```python
-import geneva
-from geneva.jobs import JobStateManager
-
-# Same credentials as lancedb.connect / the REST API
-conn = geneva.connect("db://<database>", api_key="<key>", host_override="<base_url>")
-jsm = JobStateManager(conn)
-
-# List jobs. NOTE: status defaults to "RUNNING"; pass status=None for all jobs.
-# Statuses: PENDING | RUNNING | DONE | FAILED | CANCELLED
-jobs = jsm.list_jobs(table_name="my_table", status=None)
-
-# Fetch one job by id (returns a list of JobRecord)
-records = jsm.get("<job_id>")
-```
-
-Each `JobRecord` has `table_name`, `column_name`, `job_id`, `job_type`, `status`,
-`launched_at`, `completed_at`, `config`, `launched_by`, `manifest_id`, `cluster_name`,
-`metrics` (progress counters), `events` (human-readable history), and `updated_at`.
-For filters `list_jobs` doesn't support (e.g. time ranges), query the underlying table
-directly: `jsm.get_table(True).search().where("launched_at >= TIMESTAMP '...'")` —
-pass `True` to check out the latest version, since other processes update job state.
-
-Stale-status caveat: nothing reaps dead Geneva jobs, so a job can sit in
-`RUNNING`/`PENDING` forever if its worker died. Treat a job as effectively `FAILED`
-when it has been running longer than ~36 hours, or its `updated_at` is more than ~2
-hours old (this matches the heuristic the Geneva console UI applies on read).
-
-## Workflow tips
-
-- To wait for async work (a backfill, an index build), poll `describe` until
-  `job_state` leaves `IN_PROGRESS`; on `FAILED`, pull `status` and `query_events` for
-  the failure detail.

plugins/lancedb/skills/lancedb/references/typescript/api_reference.md

@@ -1,105 +0,0 @@
-# TypeScript API Reference
-
-Quick method reference for TypeScript LanceDB code. Cross-check source for non-trivial claims.
-
-## Connect
-
-```typescript
-import * as lancedb from "@lancedb/lancedb";
-
-const db = await lancedb.connect("./camelot-db");
-```
-
-**Place the local database directory next to the script/entrypoint that opens it** (resolve the path relative to the module, e.g. via `import.meta.dirname` / `__dirname`), not buried under a shared `data/` folder. The Lance dataset is the database, not a data file — keeping it beside its code makes ownership obvious and paths stable regardless of the working directory the script is launched from.
-
-**Do not name the directory `lancedb`** (e.g. `./lancedb`, `./data/lancedb`). It collides with the imported `lancedb` package/namespace, which is confusing to read. Give it a name derived from the repo or dataset with a clear prefix/suffix — for example `./<dataset>-db`, `./<repo>_lancedb`, or `./vectordb`.
-
-Remote connections use `db://...` plus Enterprise/Cloud credentials and deployment settings. Check current source/docs for exact connection options.
-
-## Table Reads
-
-| Task | Preferred API |
-| --- | --- |
-| Vector search | `table.search(queryVector).limit(k)` |
-| Full scan with filters/projection | `table.query().where(...).select(...).limit(...)` |
-| Filter | `.where("col > 10")` |
-| Projection | `.select(["id", "text"])` |
-| Bound result count | `.limit(20)` |
-| Collect bounded result as objects | `.toArray()` on query/search result |
-| Collect bounded result as Arrow | `.toArrow()` on query/search result |
-| Stream result batches | `for await (const batch of table.query()...)` |
-
-## Local vs Remote Safety
-
-| API | Agent guidance |
-| --- | --- |
-| `table.search(...)` | Preferred read path |
-| `table.query()` | Preferred scan/filter path |
-| `await table.toArrow()` | Avoid in portable or large-table code |
-| `await table.query().toArray()` with no `limit()` | Avoid; unbounded collection |
-| `await table.query().toArrow()` with no `limit()` | Avoid; unbounded collection |
-
-## Indexes
-
-```typescript
-await table.createIndex("vector");
-await table.createIndex("status");
-```
-
-Use vector indexes for large vector search workloads and scalar indexes for filtered columns or merge/upsert keys. Check source/docs before specifying advanced index options.
-
-## Filtering And Recall Knobs
-
-```typescript
-await table.search(queryVector).where("status = 'ready'").limit(10).toArray();
-await table.search(queryVector).limit(10).refineFactor(20).toArray();
-await table.search(queryVector).limit(10).nprobes(50).toArray();
-await table.search(queryVector).limit(10).ef(100).toArray();
-await table.search(queryVector).where("status = 'ready'").postfilter().limit(10).toArray();
-```
-
-Use `postfilter()` only when fewer than `limit` results are acceptable.
-
-## Diagnostics
-
-```typescript
-console.log(await table.search(queryVector).where("year > 2000").limit(10).analyzePlan());
-console.log(await table.indexStats("vector_idx"));
-```
-
-Use these before changing indexes or search tuning.
-
-## Column (Field) Metadata
-
-```typescript
-const schema = await table.schema();
-const meta = schema.fields.find((f) => f.name === "category")?.metadata; // Map<string, string>
-const res = await table.updateFieldMetadata([
-  { path: "category", metadata: { "lancedb:description": "...", "lancedb:tag:field_type": "label" } },
-]);
-res.version; // new table version
-```
-
-Merges by default; a `null` value deletes that key; `replace: true` swaps the whole map. Nested fields use dot-paths (`"a.b.c"`). See `references/column_metadata.md` for key conventions (`lancedb:description`, `lancedb:tag:<name>`, `lancedb:logical-column`) and the authoring workflow.
-
-## Branches
-
-```typescript
-const branches = await table.branches();       // async manager
-await branches.list();                         // non-main branches; {} = only main
-const exp = await branches.create("exp");      // fork off main -> Table scoped to the branch
-const wip = await branches.checkout("wip");    // existing branch -> scoped Table (version arg pins read-only)
-const wip2 = await db.openTable("t", { branch: "wip" }); // or open scoped directly
-await branches.delete("stale");                // removes only the branch pointer
-table.currentBranch();                         // null = main
-```
-
-There is no global switch — scoping is per table handle: any read/write on a branch handle lands on that branch; the original handle keeps targeting main. See `references/branch_ops.md` for the model and isolation checks.
-
-## Maintenance
-
-```typescript
-await table.optimize();
-```
-
-Call this after every successful local/OSS ingestion. It handles compaction, cleanup of old versions according to retention, and index optimization. Do not add this for LanceDB Enterprise/Cloud remote tables; Enterprise handles compaction and cleanup automatically from cluster configuration.

plugins/lancedb/skills/lancedb/references/typescript/patterns.md

@@ -1,100 +0,0 @@
-# TypeScript Patterns
-
-Use these patterns when writing TypeScript code with `@lancedb/lancedb`.
-
-## Recommended Patterns
-
-### Bounded query
-
-Use this for application reads, scripts, and examples:
-
-```typescript
-const rows = await table
-  .query()
-  .where("status = 'ready'")
-  .select(["id", "text"])
-  .limit(20)
-  .toArray();
-```
-
-### Bounded vector search
-
-```typescript
-const rows = await table
-  .search(queryVector)
-  .select(["id", "text"])
-  .limit(20)
-  .toArray();
-```
-
-### Batch streaming for larger reads
-
-When the task needs many rows, avoid collecting everything at once:
-
-```typescript
-for await (const batch of table
-  .query()
-  .where("status = 'ready'")
-  .select(["id", "text"])
-  .limit(10_000)) {
-  process(batch);
-}
-```
-
-## Anti-Patterns
-
-**Avoid the following anti-patterns in your code.**
-
-### Table-level full materialization
-
-Avoid whole-table collectors in portable or large-table code:
-
-```typescript
-const tableArrow = await table.toArrow();
-```
-
-Why: local tables expose these whole-table collectors, but remote tables intentionally do not — a remote production table can be far larger than a local development table, so it is easy to accidentally pull the entire table into memory.
-
-### Unbounded result collection
-
-Avoid query/search collection without a meaningful limit:
-
-```typescript
-const rows = await table.query().toArray();              // unbounded plain scan
-const rows = await table.search(queryVector).toArray();  // unbounded vector search
-```
-
-Prefer `select(...).limit(...)` before collecting; for large reads, stream in batches instead.
-
-### Per-row writes
-
-Avoid loops that write one row per call:
-
-```typescript
-for (const row of rows) {
-  await table.add([row]); // one commit + fragment per row
-}
-```
-
-Each `add()` creates a new version and fragment. Pass the whole batch in a single call, or chunk very large inputs:
-
-```typescript
-await table.add(rows); // single commit
-// for very large inputs, add in chunks of several thousand rows
-```
-
-### Drop-then-reuse the same table name (Enterprise/Cloud)
-
-Avoid dropping or overwriting a remote table and then reusing that name right away:
-
-```typescript
-await db.dropTable("my_table");
-const table = await db.createTable("my_table", rows);                    // reads 500 for ~5 min
-const table = await db.createTable("my_table", rows, { mode: "overwrite" }); // same problem
-```
-
-Why: Enterprise/Cloud splits DDL (control plane) from query serving (data plane). The data plane caches the dataset behind a table name for up to `table_cache_ttl` (default 300s / 5 min), so after a drop/overwrite the DDL succeeds but queries against the reused name return `500 Internal Server Error` until the cache expires — and a fresh `describe` may still show the old schema. Instead, write to a **fresh name**, use `tableNames()` and fail if it already exists, then `renameTable(fresh, final)` onto the final name only after the old table's drop has propagated (~5 min). See the "Enterprise: never drop-then-reuse the same table name" section in `SKILL.md`. Local/OSS tables have no separate data plane — overwrite freely there.
-
-### Guessing performance fixes
-
-Avoid changing `nprobes`, `refineFactor`, `ef`, or index settings before checking `analyzePlan()` and `indexStats(...)`. Diagnose first, then tune one knob at a time.

plugins/lancedb/skills/lancedb/references/typescript/performance.md

@@ -1,78 +0,0 @@
-# TypeScript Performance Guidance
-
-Use this when writing TypeScript code that ingests data, queries large tables, builds indexes, or investigates latency.
-
-## Ingestion
-
-- Prefer bulk or batched writes.
-- Avoid per-row write loops; they create many small commits/fragments.
-- For generated data, accumulate reasonable batches before adding.
-- For file-backed data, prefer APIs that stream from Arrow/Parquet-style inputs when available.
-
-## Indexing
-
-- Build a vector index once brute-force vector search becomes too slow. As a rule of thumb, local brute force is fine below roughly 100K vectors; beyond that, build an index.
-- Use the general-purpose vector index defaults unless the task has explicit recall/latency requirements.
-- Build scalar indexes for filtered columns and merge/upsert keys.
-- Use full-text index phrase options only when phrase queries require them.
-
-## Querying
-
-Always be explicit:
-
-```typescript
-await table.search(queryVector).select(["id", "title"]).limit(20).toArray();
-```
-
-- `select()` reduces bytes read and transferred.
-- `limit()` prevents accidental full-table collection.
-- Pre-filtering is the default behavior. Use `postfilter()` only when fewer than `limit` results are acceptable.
-
-## Recall Tuning
-
-Tune one knob at a time:
-
-- Quantized indexes: raise `refineFactor(...)` to rescore more candidates on full vectors.
-- HNSW-backed indexes: raise `ef(...)`; start around `1.5 * k`, increase toward `10 * k` if recall is short.
-- IVF candidate breadth: `nprobes(...)` is usually auto-tuned; override only when a selective pre-filter leaves too few neighbors.
-
-## Maintenance
-
-After every successful embedded OSS/local ingestion, call `table.optimize()`.
-Do not add this to LanceDB Enterprise/Cloud remote table code; remote compaction
-and cleanup are handled automatically based on the Enterprise cluster
-configuration.
-
-Why local maintenance is needed:
-
-- Frequent writes can create many small fragments. Queries then need to scan across more files, which can increase latency.
-- Updates, deletes, and appends create new table versions. Old versions are retained for time travel and rollback, which can grow disk usage.
-- Indexes may have newly added rows that are not yet fully optimized into the index structure.
-
-For local/OSS tables, run `optimize()` after the final successful ingestion
-write. Also run it after later batches of update/delete operations or on a
-regular maintenance schedule:
-
-```typescript
-await table.optimize();
-```
-
-If the user wants more aggressive local disk cleanup, pass a shorter cleanup retention window:
-
-```typescript
-const olderThan = new Date(Date.now() - 24 * 60 * 60 * 1000);
-await table.optimize({ cleanupOlderThan: olderThan });
-```
-
-Do not use very short cleanup windows when the application depends on time travel, rollback, or old versions.
-
-## Diagnostics
-
-Before changing code or indexes, inspect:
-
-```typescript
-console.log(await table.search(queryVector).where("year > 2000").limit(10).analyzePlan());
-console.log(await table.indexStats("vector_idx"));
-```
-
-Look for high scan cost, missing indexes, fragmented data, and unindexed rows.

plugins/lancedb/skills/lancedb/scripts/check_materialization.py

@@ -1,135 +0,0 @@
-#!/usr/bin/env python3
-"""Scan Python and TypeScript for likely unsafe LanceDB materialization."""
-
-from __future__ import annotations
-
-import argparse
-import re
-import sys
-from dataclasses import dataclass
-from pathlib import Path
-
-
-PY_FULL_TABLE = re.compile(r"\b\w+\.(to_pandas|to_arrow|to_polars)\s*\(")
-TS_TABLE_TO_ARROW = re.compile(r"\b\w+\.toArrow\s*\(")
-TS_QUERY_COLLECTOR = re.compile(r"\.query\s*\(\s*\)[\s\S]*?\.to(Array|Arrow)\s*\(")
-
-
-@dataclass
-class Finding:
-    path: Path
-    line: int
-    message: str
-    text: str
-
-
-def iter_files(paths: list[Path]) -> list[Path]:
-    files: list[Path] = []
-    for path in paths:
-        if path.is_dir():
-            files.extend(
-                p
-                for p in path.rglob("*")
-                if p.suffix in {".py", ".ts", ".tsx"} and "node_modules" not in p.parts
-            )
-        elif path.suffix in {".py", ".ts", ".tsx"}:
-            files.append(path)
-    return sorted(set(files))
-
-
-def line_number(text: str, offset: int) -> int:
-    return text.count("\n", 0, offset) + 1
-
-
-def scan_python(path: Path, text: str) -> list[Finding]:
-    findings: list[Finding] = []
-    for match in PY_FULL_TABLE.finditer(text):
-        line_start = text.rfind("\n", 0, match.start()) + 1
-        line_end = text.find("\n", match.start())
-        if line_end == -1:
-            line_end = len(text)
-        line = text[line_start:line_end].strip()
-        if ".search(" in line or ".query(" in line:
-            continue
-        findings.append(
-            Finding(
-                path,
-                line_number(text, match.start()),
-                f"Review Python `{match.group(1)}()` call; table-level materialization is not portable to remote tables.",
-                line,
-            )
-        )
-    return findings
-
-
-def statement_around(text: str, start: int, end: int) -> str:
-    before = max(text.rfind(";", 0, start), text.rfind("\n\n", 0, start))
-    after_candidates = [pos for pos in (text.find(";", end), text.find("\n\n", end)) if pos != -1]
-    after = min(after_candidates) if after_candidates else len(text)
-    return text[before + 1 : after].strip()
-
-
-def scan_typescript(path: Path, text: str) -> list[Finding]:
-    findings: list[Finding] = []
-    for match in TS_TABLE_TO_ARROW.finditer(text):
-        stmt = statement_around(text, match.start(), match.end())
-        if ".query(" in stmt or ".search(" in stmt:
-            continue
-        findings.append(
-            Finding(
-                path,
-                line_number(text, match.start()),
-                "Review TypeScript `table.toArrow()`-style call; table-level materialization is not portable for large/remote tables.",
-                stmt.splitlines()[0].strip(),
-            )
-        )
-
-    for match in TS_QUERY_COLLECTOR.finditer(text):
-        stmt = statement_around(text, match.start(), match.end())
-        if ".limit(" in stmt:
-            continue
-        findings.append(
-            Finding(
-                path,
-                line_number(text, match.start()),
-                "Review unbounded TypeScript query collection; add `limit()` or stream batches.",
-                stmt.splitlines()[0].strip(),
-            )
-        )
-    return findings
-
-
-def scan_file(path: Path) -> list[Finding]:
-    text = path.read_text(encoding="utf-8", errors="replace")
-    if path.suffix == ".py":
-        return scan_python(path, text)
-    if path.suffix in {".ts", ".tsx"}:
-        return scan_typescript(path, text)
-    return []
-
-
-def main() -> int:
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument("paths", nargs="+", type=Path)
-    parser.add_argument(
-        "--no-fail", action="store_true", help="Always exit 0 after reporting findings."
-    )
-    args = parser.parse_args()
-
-    findings: list[Finding] = []
-    for path in iter_files(args.paths):
-        findings.extend(scan_file(path))
-
-    for finding in findings:
-        print(f"{finding.path}:{finding.line}: {finding.message}")
-        print(f"  {finding.text}")
-
-    if findings:
-        print(
-            f"\n{len(findings)} finding(s). Review manually; bounded query result conversion may be OK."
-        )
-    return 0 if args.no_fail or not findings else 1
-
-
-if __name__ == "__main__":
-    sys.exit(main())

python/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lancedb-python"
-version = "0.37.1-beta.0"
+version = "0.38.0-beta.3"
 publish = false
 edition.workspace = true
 description = "Python bindings for LanceDB"
@@ -15,10 +15,10 @@ name = "_lancedb"
 crate-type = ["cdylib"]
 
 [dependencies]
-arrow = { version = "58.0.0", features = ["pyarrow"] }
-async-trait = "0.1"
-bytes = "1"
-lancedb = { path = "../rust/lancedb", default-features = false }
+arrow = { workspace = true, features = ["pyarrow"] }
+async-trait.workspace = true
+bytes.workspace = true
+lancedb.workspace = true
 datafusion-common.workspace = true
 lance-core.workspace = true
 lance-namespace.workspace = true
@@ -26,24 +26,24 @@ lance-namespace-impls.workspace = true
 lance-io.workspace = true
 env_logger.workspace = true
 log.workspace = true
-pyo3 = { version = "0.28", features = ["extension-module", "abi3-py39", "chrono"] }
-chrono = { version = "0.4", default-features = false, features = ["clock"] }
+pyo3 = { version = "0.28", features = ["extension-module", "abi3-py310", "chrono"] }
+chrono.workspace = true
 pyo3-async-runtimes = { version = "0.28", features = [
     "attributes",
     "tokio-runtime",
 ] }
-pin-project = "1.1.5"
+pin-project.workspace = true
 futures.workspace = true
-serde = "1"
-serde_json = "1"
+serde.workspace = true
+serde_json.workspace = true
 snafu.workspace = true
-tokio = { version = "1.40", features = ["sync", "rt-multi-thread"] }
+tokio.workspace = true
 libc = "0.2"
 
 [build-dependencies]
 pyo3-build-config = { version = "0.28", features = [
     "extension-module",
-    "abi3-py39",
+    "abi3-py310",
 ] }
 
 [features]

python/pyproject.toml

@@ -8,7 +8,7 @@ dependencies = [
     "overrides>=0.7; python_version<'3.12'",
     "packaging>=23.0",
     "pyarrow>=16",
-    "pydantic>=1.10",
+    "pydantic>=2.7.4,<3",
     "tqdm>=4.27.0",
     "lance-namespace>=0.3.2"
 ]
@@ -60,7 +60,7 @@ tests = [
     "pytest-asyncio>=0.21",
     "duckdb>=0.9.0",
     "pytz>=2023.3",
-    "polars>=0.19, <=1.3.0",
+    "polars>=0.19, <=1.32.3",
     "pyarrow<25",
     "pyarrow-stubs>=16.0",
     "pylance==9.0.0rc1",
@@ -140,6 +140,7 @@ include = [
     "python/lancedb/remote/errors.py",
     "python/lancedb/embeddings/__init__.py",
     "python/lancedb/_lancedb.pyi",
+    "python/type_tests/connect.py",
 ]
 exclude = ["python/tests/"]
 pythonVersion = "3.13"

python/python/lancedb/__init__.py

@@ -12,6 +12,7 @@ __version__ = importlib.metadata.version("lancedb")
 
 from ._lancedb import connect as lancedb_connect
 from ._lancedb import FtsToken
+from ._lancedb import LsmWriteSpec
 from ._lancedb import tokenize as _tokenize
 from .common import URI, sanitize_uri
 from urllib.parse import urlparse
@@ -21,6 +22,16 @@ from .remote.db import RemoteDBConnection
 from .expr import Expr, col, lit, func
 from .schema import blob, vector, BlobType
 from .job import AsyncJob, Job
+from .functions import (
+    FunctionArtifactRequest as FunctionArtifactRequest,
+    FunctionApplication as FunctionApplication,
+    FunctionBinding as FunctionBinding,
+    FunctionRegistrationRequest as FunctionRegistrationRequest,
+    FunctionVersion as FunctionVersion,
+    PythonRuntimeSpec as PythonRuntimeSpec,
+    UdfDefinition as UdfDefinition,
+    udf as udf,
+)
 from .table import AsyncTable, Table
 from .types import BaseTokenizerType
 from ._lancedb import Session
@@ -518,6 +529,7 @@ __all__ = [
     "Job",
     "LanceDBConnection",
     "LanceNamespaceDBConnection",
+    "LsmWriteSpec",
     "RemoteDBConnection",
     "Session",
     "Table",

python/python/lancedb/_lancedb.pyi

@@ -147,6 +147,8 @@ class Connection(object):
         limit: Optional[int],
     ) -> list[str]: ...  # Deprecated: Use list_tables instead
     def job(self, job_id: str) -> Job: ...
+    async def create_function_async(self, request_json: str) -> FunctionJob: ...
+    async def get_function(self, name: str, version: str) -> str: ...
     async def list_jobs(self) -> List[JobInfo]: ...
     async def get_job(self, job_id: str) -> Optional[JobDescription]: ...
     async def cancel_job(self, job_id: str) -> bool: ...
@@ -198,6 +200,9 @@ class Connection(object):
     async def drop_table(
         self, name: str, namespace_path: Optional[List[str]] = None
     ) -> None: ...
+    async def drop_table_async(
+        self, name: str, namespace_path: Optional[List[str]] = None
+    ) -> Job: ...
     async def drop_all_tables(
         self, namespace_path: Optional[List[str]] = None
     ) -> None: ...
@@ -223,6 +228,13 @@ class Job:
     async def wait(self) -> None: ...
     async def cancel(self) -> None: ...
 
+class FunctionJob:
+    @property
+    def id(self) -> Optional[str]: ...
+    async def status(self) -> str: ...
+    async def wait(self) -> str: ...
+    async def cancel(self) -> None: ...
+
 class JobInfo:
     @property
     def job_id(self) -> str: ...
@@ -335,6 +347,14 @@ class Table:
     ) -> list[FtsToken]: ...
     async def delete(self, filter: Union[str, PyExpr]) -> DeleteResult: ...
     async def add_columns(self, columns: list[tuple[str, str]]) -> AddColumnsResult: ...
+    async def add_computed_columns(
+        self, columns: list[tuple[str, str]]
+    ) -> AddColumnsResult: ...
+    async def add_function_columns(
+        self, application_json: str, output_name: Optional[str]
+    ) -> AddColumnsResult: ...
+    async def refresh_column(self, column: str) -> RefreshColumnResult: ...
+    async def refresh_column_async(self, column: str) -> Job: ...
     async def add_columns_with_schema(self, schema: pa.Schema) -> AddColumnsResult: ...
     async def alter_columns(
         self, columns: list[dict[str, Any]]
@@ -355,6 +375,10 @@ class Table:
     async def set_lsm_write_spec(self, spec: LsmWriteSpec) -> None: ...
     async def unset_lsm_write_spec(self) -> None: ...
     async def get_lsm_write_spec(self) -> Optional[LsmWriteSpec]: ...
+    async def checkpoint_lsm(self) -> None: ...
+    async def flush_lsm(self) -> None: ...
+    async def compact_lsm(self) -> None: ...
+    async def get_lsm_stats(self, include_generation_rows: bool) -> Optional[dict]: ...
     async def close_lsm_writers(self) -> None: ...
     @property
     def tags(self) -> Tags: ...
@@ -649,9 +673,10 @@ class LsmWriteSpec:
     def identity(column: str) -> "LsmWriteSpec": ...
     @staticmethod
     def unsharded() -> "LsmWriteSpec": ...
-    def with_maintained_indexes(self, indexes: List[str]) -> "LsmWriteSpec":
-        """Return a copy of this spec asking the MemWAL to keep the named
-        indexes up to date as rows are appended."""
+    def with_maintained_indexes(self, indexes: Optional[List[str]]) -> "LsmWriteSpec":
+        """Set which indexes the MemWAL keeps up to date. None resolves every
+        index on the table at install, failing if one cannot be maintained;
+        a list is verbatim, empty means none."""
         ...
     def with_writer_config_defaults(self, defaults: Dict[str, str]) -> "LsmWriteSpec":
         """Return a copy of this spec recording the given default
@@ -666,13 +691,19 @@ class LsmWriteSpec:
     @property
     def num_buckets(self) -> Optional[int]: ...
     @property
-    def maintained_indexes(self) -> List[str]: ...
+    def maintained_indexes(self) -> Optional[List[str]]:
+        """Indexes the MemWAL keeps up to date, or None for every supported one."""
+        ...
     @property
     def writer_config_defaults(self) -> Dict[str, str]: ...
 
 class AddColumnsResult:
     version: int
 
+class RefreshColumnResult:
+    rows_filled: int
+    version: int
+
 class AlterColumnsResult:
     version: int