## Summary
- add `StreamingDataLoader`, which transports worker snapshots with
prefetched batches and commits them to the parent dataset only when the
trainer receives each batch
- preserve exact non-uniform per-split progress and resume lagging
splits without replaying already-consumed rows
- reject stale parent checkpoints after a standard multi-process
`DataLoader` has started, with guidance to use the consumer-aware loader
- document the new public loader and merge non-uniform state across
ranks
## Root cause
PyTorch runs `StreamingDataset.__iter__` in private worker-process
copies, while callers invoke `state_dict()` on the parent dataset.
Sharing producer counters would still be incorrect because DataLoader
prefetch can advance workers beyond batches returned to the trainer.
## Validation
- `uv run --extra tests pytest python/tests/test_elastic_dataloader.py
-q` (154 passed)
- focused non-uniform merge regression (1 passed)
- `uv run --project python --extra tests --extra dev ruff format .`
- `uv run --project python --extra tests --extra dev ruff check .`
- `cd docs && PYTHONPATH=. ../python/.venv/bin/mkdocs build`
Fixes#3967
<!-- lance-gatekeeper-fix:v1 agent=572be272619660b97e87fd5c85188341
generation=1 -->
---------
Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
Co-authored-by: Xuanwo <github@xuanwo.io>
Exposes materialized views to Python in both the async and sync clients:
create_materialized_view / open_materialized_view /
list_materialized_views
on the connections, and MaterializedView / AsyncMaterializedView handles
carrying the parsed definition and refresh(full=, source_version=),
which
returns the typed refresh result. select accepts column names, (alias,
expression) pairs, or a dict of the same; the definition reads back off
the
stored schema, so a reopened handle needs no side channel. Remote
connections raise NotImplementedError up front rather than failing deep
in
a request, matching the computed-column convention.
<sub>Stack created with <a
href="https://github.com/github/gh-stack">GitHub Stacks CLI</a> • <a
href="https://gh.io/stacks-feedback">Give Feedback 💬</a></sub>
## Problem
The canonical Function wire values and typed remote Job contract do not
yet provide a Python authoring surface or catalog client, so users
cannot package a scalar callable, register it, or reopen the exact
immutable Function version.
## Behavior
This adds scalar-only `@udf` authoring with deterministic annotation or
explicit Arrow schema validation, content-addressed Python artifacts,
and an internal scalar-to-Arrow-batch adapter descriptor. Registration
payloads model non-secret environment values and secret names only.
Remote connections can submit `create_function_async` and receive a
typed `Job<FunctionVersion>`, then reopen that exact version by name and
version ID. Synchronous connections can call `create_function` to submit
and wait for the immutable version in one operation. Local Function
catalog operations return a stable `NotSupported` error. Shared
Rust/Python golden payloads and mocked catalog responses freeze the
request, typed terminal result, and exact lookup contract.
## Validation
- Rust formatting, remote check, clippy, and focused LDB-1/LDB-2 tests
- Python formatting, lint, and focused LDB-1/LDB-2 tests
- Python API documentation build
## Problem
Enterprise Function-backed computed columns need a stable SDK contract
before Sophon catalog and execution endpoints can be added. The existing
`Job` API can only represent unit terminal results, and there is no
shared Rust/Python wire definition for immutable Function versions,
applications, bindings, or refresh results.
## Behavior
This introduces remote-only canonical Function values in Rust and
Python, evolves `Job<T = ()>` to decode typed remote terminal results
while keeping local spawned operations unit-typed, and fixes the
cross-language contract with shared JSON golden fixtures. Unknown fields
and discriminator values remain forward-decodable, while canonical
output contains only fields known to the client. Function models contain
secret names only.
Sophon remains the sole owner of catalog persistence, environment bake,
secret resolution, execution, and publication. This PR does not add
authoring/catalog endpoints, local execution, refresh runners, or live
Sophon E2E coverage.
## Why
Four of the eight LSM methods are **remote-only in the core**. `impl
BaseTable for NativeTable` implements only
`set`/`unset`/`get_lsm_write_spec` and `close_lsm_writers`; `flush_lsm`,
`compact_lsm` and `get_lsm_stats` fall through to trait defaults
returning `NotSupported` (`rust/lancedb/src/table.rs:679,687,696`), and
`checkpoint_lsm` is built on all three.
That explains the state of the bindings: Node had bound the four that
work against a local table and stopped, so a Cloud user could install an
LSM write spec but had no way to observe fresh-tier state or drive a
checkpoint. Java had none of it at all.
| SDK | set/unset/get spec | closeWriters | flush | compact | getStats |
checkpoint |
|---|---|---|---|---|---|---|
| Rust core | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Python | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Node *(before)* | ✅ | ✅ | — | — | — | — |
| **Node (after)** | ✅ | ✅ | **new** | **new** | **new** | **new** |
| Java *(before)* | — | — | — | — | — | — |
| **Java (after)** | **new** | n/a | **new** | **new** | **new** |
**new** |
Go and C are separate repos and are out of scope here. `closeLsmWriters`
drains cached in-process shard writers, so it has no meaning for Java,
which is a pure REST client.
## Node
Adds napi bindings for `flushLsm`, `compactLsm`, `checkpointLsm` and
`getLsmStats`, plus typed `LsmStats` / `BucketStats` / `GenerationStats`
/ `MemtableStats` objects — typed rather than a JSON blob, matching the
existing `LsmWriteSpec` object in the same file, with `u64` cast to
`i64` per that file's convention.
Because these four are remote-only, the new tests assert each binding
reaches the core and surfaces `NotSupported` against a local table. That
covers the wiring; behavior against a real endpoint stays covered by the
mocked-endpoint tests in `rust/lancedb/src/remote/table.rs`.
## Python
No new methods. All eight are on `LanceTable`, `AsyncTable` and
`RemoteTable` — the last four landed on the sync `RemoteTable` in #3961,
which is merged into this branch.
What was missing here was reachability. `LsmWriteSpec` was importable
only from the private `lancedb._lancedb`, appearing in `table.py` solely
under `if TYPE_CHECKING:`, and `docs/src/python/python.md` had no
mention of it, which per the repo's docs guidance means it rendered
nowhere in the API reference. It is now `lancedb.LsmWriteSpec`, in
`__all__`, and documented.
## Java
Java reaches LanceDB purely over REST through the generated Lance
Namespace client, and these routes are not in that spec, so they are
issued through a small dedicated client rather than added to the spec.
That call is revisitable — LSM is one of four unspecified route families
alongside `multipart_write`, `page_cache/prewarm` and
`branches/diff|merge`. If those are ever regularized into the spec as a
group, `LanceDbTableLsm` is one file that gets deleted.
`LsmWriteSpec` here is deliberately **not**
`org.lance.memwal.InitializeMemWalParams`. That type defaults to
maintaining *no* indexes where a spec here defaults to maintaining
*every* index, and it cannot express the `null` that asks the server to
resolve the set:
| Value | On the wire | Meaning |
|---|---|---|
| unset (null) | `null` | Server resolves **every** maintainable index |
| `Collections.emptyList()` | `[]` | Maintain **none** |
| `Arrays.asList("id_idx")` | `["id_idx"]` | Exactly those |
A dedicated test pins null and `[]` as distinct on the wire, since
collapsing them is the failure mode that motivated a LanceDB-owned type.
`checkpointLsm` is ported from `rust/lancedb/src/table/checkpoint.rs`
with its constants and status semantics intact: 429/503 retried in place
against an 8-budget, 421 restarting from flush against a 3-budget, 5s
poll, and a target watermark fixed after the seal so it terminates under
write load.
`getLsmStats` returns typed `LsmStats` / `BucketStats` /
`GenerationStats` / `MemtableStats`, mirroring the Rust structs in
`rust/lancedb/src/table/lsm_stats.rs` and the objects Node exposes.
Decoding is strict — see below.
## Review feedback
Both gatekeeper findings were real. Each was reproduced against the
scripted test server first, and each fix ships with the reproducer as a
regression test.
**The transport was doubling every checkpoint retry budget.**
`HttpClients.createDefault()` installs Apache's default response retry
strategy, whose retryable-status list is exactly 429 and 503 — the two
statuses `isRetryable` owns. A 429 held against `flush_lsm` issued
**18** wire requests where the loop intends 9, and `compact_lsm` was
retried in place despite the loop being built to fall through to a fresh
stats poll instead. Timing confirmed the mechanism: that run took 25.4s
≈ 16.3s of the loop's own backoff plus 9 × the transport's 1s retry
interval.
Automatic retries are now disabled, so the checkpoint loop is the sole
owner of the 421/429/503 transitions. A side effect worth noting:
`testCheckpointRetriesRetryableStatusInPlace` was passing on a
transport-absorbed 429 and never reaching `issue()`'s retry branch at
all. It now exercises the real path.
**Stats decoding failed open.** `getLsmStats` read the response with
Jackson's `path()`, which yields a missing node that iterates as an
empty array — making "malformed" indistinguishable from "no buckets",
which is indistinguishable from "drained". Four separate payloads made
`checkpointLsm()` report convergence for a checkpoint that never ran:
| Response | Before | Now |
|---|---|---|
| `{"lsm_stats": null}` or absent key | disabled ✓ | disabled ✓ |
| `{"lsm_stats": {}}` | **reported success** | `IllegalStateException` |
| empty response body | **reported success** | `IllegalStateException` |
| bucket missing required fields | **reported success** |
`IllegalStateException` |
The empty-body row is the one to weight: a proxy 200 with no body is a
realistic production event, and it silently reported a checkpoint that
never happened.
Decoding is now strict and fails closed, matching the serde contract on
the Rust side exactly. One deliberate deviation from the review comment,
which asked that *only* explicit JSON `null` count as disabled: Rust has
`#[serde(default)]` on `lsm_stats`, so an **absent key** decodes to
`None` there too. Java now matches that. It is an absent-or-malformed
**`buckets`** that fails closed, which is the case the comment was
actually protecting.
## Testing
- Java: **33 passing** (8 existing + 25 LSM) against a scripted
`com.sun.net.httpserver.HttpServer` — no new test dependency. Wire
assertions mirror `rust/lancedb/src/remote/table.rs:6581-6748`;
checkpoint tests cover convergence, not piling onto a latched bucket,
421 restart-from-flush, 429 retry-in-place, terminal-status propagation,
reissue exhaustion, the exact wire-request count against the retry
budget, and five malformed stats payloads.
- Node: **19 LSM tests passing**; `cargo check`, `npm run build`, `npm
run tsc`, `npm run lint`, `npm run docs` all clean.
- Python: `ruff format --check` and `ruff check` clean.
- Java formatting: `./mvnw -pl lancedb-core spotless:apply` and
`spotless:check` both clean under a JDK 11 toolchain.
## Note: spotless needs a pre-16 JDK
`./mvnw spotless:apply` fails on JDK 16+ with
`JCTree$JCImport.getQualifiedIdentifier()` — google-java-format 1.7,
pinned at `java/pom.xml:34`, predates JDK 16's compiler API change.
**This is pre-existing** and reproduces on a pristine `main` checkout.
It is not a blocker, just a toolchain requirement. Spotless was run
against these sources under JDK 11 and both `spotless:apply` and
`spotless:check` pass on the whole module:
```shell
JAVA_HOME=/path/to/jdk11 ./mvnw -pl lancedb-core spotless:apply
```
Bumping the plugin so it works on modern JDKs is still worth doing, but
separately from this PR.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
The docs have no link checking at all, so external links rot silently: a
trial run already found `docs/src/python/python.md` pointing at
`lancedb.github.io/lance-namespace`, which returns 404 since the
repository moved to the lance-format org.
Checking external links on the blocking path would be the wrong trade:
third-party hosts rate-limit automated clients, reject non-browser user
agents, and go down temporarily, so any of them having a bad minute
would turn unrelated PRs red. Following lance-format/lance#8315, this
adds a daily `lychee` run that reports broken links into a single
tracking issue, rewritten in place on each run and closed automatically
once every link resolves. The scan job runs the downloaded lychee binary
with a read-only token; everything that writes lives in a separate
report job, and a non-verdict lychee exit fails the run instead of
publishing a bogus report.
The check is restricted to http(s) links because much of `docs/src` is
generated API reference (the `js/` tree comes from `npm run docs`) and
the hand-written pages use mkdocstrings cross-references and
nav-relative paths that only resolve in the site mkdocs builds, so
relative links would be reported as broken on every run.
The one broken link the trial run surfaced is fixed here; after the fix,
a local run over all 154 files reports 0 errors across 216 unique links.
`docs/src/python/python.md` is the whole Python API reference, but it is
maintained by hand and had drifted from the public API. Anything not
listed there simply doesn't get rendered, so a number of public,
documented, tested APIs were invisible to users — most notably branch
management, where `diff` and `merge` live.
I audited every public symbol reachable from `lancedb` and its
subpackages against the `:::` directives on the page. This adds the
missing ones:
- **Branching** — `Branches`, `AsyncBranches` (`list` / `create` /
`checkout` / `delete` / `diff` / `merge`)
- **Tables** — `TableStatistics` (returned by `Table.stats()`; the
fragment-level stats classes were already listed)
- **Full text queries** — `FullTextQuery`, `MatchQuery`, `PhraseQuery`,
`BoostQuery`, `MultiMatchQuery`, `BooleanQuery`, `FullTextOperator`,
`Occur`
- **Querying** — `LanceEmptyQueryBuilder`, `LanceTakeQueryBuilder`,
`AsyncTakeQuery`
- **Indices** — `Fm` (the FM-index for substring search), `IndexConfig`
- **Blobs** — `blob`, `BlobType`, `BlobFile`
- **Namespaces** — `connect_namespace`, `connect_namespace_async`, and
both namespace connection classes
- **Remote config** — `TlsConfig`, `HeaderProvider`, `OAuthConfig`,
`OAuthFlowType`
- **Rerankers** — the `Reranker` base class plus `JinaReranker`,
`RRFReranker`, `MRRReranker`, `AnswerdotaiRerankers`,
`VoyageAIReranker`, `WatsonxReranker` (5 of 12 were listed)
- **Embeddings** — `get_registry`, `register`, and the 14 embedding
functions that were missing (3 of 17 were listed)
- **PyTorch** — `StreamingDataset` and the permutation API it is built
on
- **Misc** — `Session`, `tokenize`, `FtsToken`, `pydantic.Vector`,
`pydantic.MultiVector`, `instrument_lancedb_metrics`, and the two
exception types
It also repairs cross-references in docstrings that no longer resolve:
links into guide pages that have since moved to lancedb.com
(`querying-an-ann-index`, `experimental-full-text-search`),
`lance.dataset` references with no inventory behind them, and the
relative targets `[Table](Table)` and `[PyArrow Table](pyarrow.Table)`.
Deliberately left out: concrete implementation classes reached through
their abstract base (`LanceTable`, `LanceDBConnection`,
`RemoteDBConnection`), query base classes already covered by
`inherited_members: true`, and internal plumbing such as
`FullTextSearchQuery` and `ColumnOrdering`.
## Testing
The docs job only runs on pushes to `main`, so I built the site locally
and compared against a build of `upstream/main`: every added entry
resolves, and no symbol that was rendered before stopped being rendered
when the four packages moved to automodule. `mkdocs build --strict`
exits 0 on this branch, against 61 warnings on `main`.
## Also in this PR
`lancedb.index`, `lancedb.embeddings`, `lancedb.remote` and
`lancedb.rerankers` are now rendered by a single mkdocstrings directive
each, driven by the module's `__all__`, rather than a hand-maintained
list. These four are where most of the drift was, and `__all__` is
harder to forget than a docs page. `lancedb.embeddings` had no
`__all__`; without one mkdocstrings renders no members at all for a
re-export package, so one is added. AGENTS.md gains a section on how the
page is wired up and how to build the docs locally.
Rendering all that code for the first time surfaced ~100 more build
warnings, which would have made #3707 (turning on `mkdocs build
--strict`) harder to land, so the warning backlog is cleared here too.
97 of the 158 warnings were one systematic false positive — griffe
cannot see the generated `__init__` of a pydantic dataclass, so every
documented parameter looks unknown — switched off via
`warn_unknown_params`. The remaining 61 came from 15 docstrings with
real bugs: prose trailing a `Parameters` section (we were rendering
parameters called `The`, `you` and `To`), types dropped because numpydoc
needs spaces around the colon, `num_partitions, default sqrt(num_rows)`
parsing as a list of names and inventing a `default` parameter, and one
parameter indented five spaces. `mkdocs build --strict` now exits 0.
---
#3747 (the coverage test that keeps this from happening again) is
stacked on this branch, so review it after this one.
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
## What
Expose custom FTS stop-word lists in the Python and TypeScript public
APIs, including their standalone tokenize helpers and remote index
creation.
This PR supports concrete string lists only. It does not add file or
LanceDB-table stop-word sources.
## Why
Rust already exposes Lance's custom stop-word list option. The Python
and TypeScript APIs did not pass it through, and local index details did
not retain the full tokenizer parameters needed by index-backed
tokenization after reopening a table.
## How
- Add `custom_stop_words` / `customStopWords` to the Python and
TypeScript FTS and tokenize options.
- Preserve `None` / `undefined`, empty lists, and list contents without
normalization.
- Load the persisted FTS segment parameters when returning local index
details.
- Serialize the concrete list in remote create-index requests.
- Keep Python and TypeScript tests thin; behavior, persistence, query
tokenization, and remote JSON coverage live primarily in Rust.
## Validation
- `cargo check --quiet --features remote --tests --examples`
- `cargo clippy --quiet --features remote --tests --examples`
- `cargo test --quiet --features remote --tests`
- Python extension rebuild with `uv` and `maturin`
- Targeted Python tests: 4 passed
- Python `ruff format --check` and `ruff check`
- TypeScript build, typecheck, Biome lint, generated docs, and targeted
tests
---------
Co-authored-by: Yang Cen <yangcen@Yangs-Mac-mini.local>
Adds three index configuration classes to the Python API Reference that
were missing from the documentation:
- `IvfSq` - IVF Scalar Quantization index
- `IvfRq` - IVF RabitQ Quantization index
- `HnswFlat` - HNSW without quantization (stores raw vectors)
These classes are exported in `lancedb.index.__all__` and have complete
docstrings in the source, but weren't showing up in the rendered docs at
https://lancedb.github.io/lancedb/python/python/#indices-asynchronous.
Closes#1855
This wires Lance's existing `jieba/*` and `lindera/*` native FTS
tokenizers through the Python SDK instead of leaving them behind
disabled features and narrow public typing. It also documents the
`LANCE_LANGUAGE_MODEL_HOME` model layout and adds Python coverage for
successful CJK indexing plus missing-model error guidance.
Closes#2168.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **Documentation**
- Expanded Python API reference with new entries for table metadata,
tagging, remote client configuration, and index statistics.
- Added documentation for new classes and modules in both synchronous
and asynchronous sections, including `FragmentStatistics`,
`FragmentSummaryStats`, `Tags`, `AsyncTags`, `IndexStatistics`, and
remote configuration options.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
This PR does the following:
- Pare down the docs to only what's needed (Python, JS/TS API docs and a
pointer to Rust docs)
- Styling changes to be more in line with the main website theme
The relative URLs remain unchanged, so assuming CI passes, there should
be no breaking changes from the main docs site that points back here.
This includes several improvements and fixes to the Python Async query
builders:
1. The API reference docs show all the methods for each builder
2. The hybrid query builder now has all the same setter methods as the
vector search one, so you can now set things like `.distance_type()` on
a hybrid query.
3. Re-rankers are now properly hooked up and tested for FTS and vector
search. Previously the re-rankers were accidentally bypassed in unit
tests, because the builders overrode `.to_arrow()`, but the unit test
called `.to_batches()` which was only defined in the base class. Now all
builders implement `.to_batches()` and leave `.to_arrow()` to the base
class.
4. The `AsyncQueryBase` and `AsyncVectoryQueryBase` setter methods now
return `Self`, which provides the appropriate subclass as the type hint
return value. Previously, `AsyncQueryBase` had them all hard-coded to
`AsyncQuery`, which was unfortunate. (This required bringing in
`typing-extensions` for older Python version, but I think it's worth
it.)
binary vectors and hamming distance can work on only IVF_FLAT, so
introduce them all in this PR.
---------
Signed-off-by: BubbleCal <bubble-cal@outlook.com>
### Changes to sync API
* Updated `LanceTable` and `LanceDBConnection` reprs
* Add `storage_options`, `data_storage_version`, and
`enable_v2_manifest_paths` to sync create table API.
* Add `storage_options` to `open_table` in sync API.
* Add `list_indices()` and `index_stats()` to sync API
* `create_table()` will now create only 1 version when data is passed.
Previously it would always create two versions: 1 to create an empty
table and 1 to add data to it.
### Changes to async API
* Add `embedding_functions` to async `create_table()` API.
* Added `head()` to async API
### Refactors
* Refactor index parameters into dataclasses so they are easier to use
from Python
* Moved most tests to use an in-memory DB so we don't need to create so
many temp directories
Closes#1792Closes#1932
---------
Co-authored-by: Weston Pace <weston.pace@gmail.com>
This PR makes incremental changes to the documentation.
* Closes#697
* Closes#698
- [x] Add dark mode
- [x] Fix headers in navbar
- [x] Add `extra.css` to customize navbar styles
- [x] Customize fonts for prose/code blocks, navbar and admonitions
- [x] Inspect all admonition boxes (remove redundant dropdowns) and
improve clarity and readability
- [x] Ensure that all images in the docs have white background (not
transparent) to be viewable in dark mode
- [x] Improve code formatting in code blocks to make them consistent
with autoformatters (eslint/ruff)
- [x] Add bolder weight to h1 headers
- [x] Add diagram showing the difference between embedded (OSS) and
serverless (Cloud)
- [x] Fix [Creating an empty
table](https://lancedb.github.io/lancedb/guides/tables/#creating-empty-table)
section: right now, the subheaders are not clickable.
- [x] In critical data ingestion methods like `table.add` (among
others), the type signature often does not match the actual code
- [x] Proof-read each documentation section and rewrite as necessary to
provide more context, use cases, and explanations so it reads less like
reference documentation. This is especially important for CRUD and
search sections since those are so central to the user experience.
- [x] The section for [Adding
data](https://lancedb.github.io/lancedb/guides/tables/#adding-to-a-table)
only shows examples for pandas and iterables. We should include pydantic
models, arrow tables, etc.
- [x] Add conceptual tutorial for IVF-PQ index
- [x] Clearly separate vector search, FTS and filtering sections so that
these are easier to find
- [x] Add docs on refine factor to explain its importance for recall.
Closes#716
- [x] Add an FAQ page showing answers to commonly asked questions about
LanceDB. Closes#746
- [x] Add simple polars example to the integrations section. Closes#756
and closes#153
- [ ] Add basic docs for the Rust API (more detailed API docs can come
later). Closes#781
- [x] Add a section on the various storage options on local vs. cloud
(S3, EBS, EFS, local disk, etc.) and the tradeoffs involved. Closes#782
- [x] Revamp filtering docs: add pre-filtering examples and redo headers
and update content for SQL filters. Closes#783 and closes#784.
- [x] Add docs for data management: compaction, cleaning up old versions
and incremental indexing. Closes#785
- [ ] Add a benchmark section that also discusses some best practices.
Closes#787
---------
Co-authored-by: Ayush Chaurasia <ayush.chaurarsia@gmail.com>
Co-authored-by: Will Jones <willjones127@gmail.com>
Adds:
* Make `mkdocstrings` aware we are using numpy-style docstrings
* Fixes broken link on `index.md` to Python API docs (and added link to
node ones)
* Added examples to various classes.
* Added doctest to verify examples work.
lancedb-gatefixer[bot]
Wyatt Alt
Xuanwo
Dan Rammer
Will Jones
Yang Cen
Vishal Kumar Singh
Pratik Dey
Prashanth Rao
Renato Marroquin
Lei Xu
Weston Pace
Chang She
QianZhu
Ayush Chaurasia
Jai