Files
lancedb/docs
lancedb-gatefixer[bot]andXuanwo c167b99fa0 fix: read legacy blob columns through blob APIs (#4649)
Legacy blob v1 columns were rejected by LanceDB's blob validation and
omitted from `blob_columns()`, even though the pinned Lance reader
already supports them. Accept both blob versions in read validation and
discovery so `fetch_blobs`, `fetch_blob_files`, and `fetch_blob_ranges`
can read legacy payloads through the existing native reader.

Keep list-nested blobs excluded from row-based reads and document how to
fetch legacy blobs using explicit row IDs. Regression coverage checks
sync and async APIs, independently written Lance datasets, ordering and
duplicates across fragments, null and empty blobs, lazy seeking, ranges,
and deleted rows.

Fixes #4644

Validation:

- Both new Python regressions failed on the original implementation with
the reported legacy-column rejection and empty discovery result, then
passed with the fix.
- Python blob suite: 202 passed, 1 skipped.
- Remote blob tests: 29 passed.
- Focused Rust blob unit tests with `remote`: 13 passed.
- Rust blob integration suite with `remote`: 59 passed, including legacy
storage 2.0 and 2.1.
- Rust compile and Clippy checks with `remote`, tests, and examples
passed.
- Python package Ruff lint and format checks passed; Rust formatting
passed.
- Repository-wide `ruff check .` reports 49 existing errors in unchanged
`docs/web-tests` examples; the Python package is clean.

<!-- lance-gatekeeper-fix:v1 agent=02b7edcbfa8ff0e7fad4615159249b3e
generation=1 -->

---------

Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
Co-authored-by: Xuanwo <github@xuanwo.io>
2026-10-27 19:56:50 +08:00
..
2026-09-09 15:33:04 +08:00

LanceDB Documentation

LanceDB docs are available at docs.lancedb.com.

The SDK docs are built and deployed automatically by Github Actions whenever a commit is pushed to the main branch. So it is possible for the docs to show unreleased features.

Building the docs

Setup

  1. Install LanceDB Python. See setup in Python contributing guide. Run make develop to install the Python package.
  2. Install documentation dependencies. From LanceDB repo root: pip install -r docs/requirements.txt

Preview the docs

Run these commands from the LanceDB repository root. The subshell changes into docs to load mkdocs.yml, while leaving your shell in the repository root.

(cd docs && PYTHONPATH=. mkdocs serve)

If you want to just generate the HTML files:

(cd docs && PYTHONPATH=. mkdocs build)

If successful, you should see a docs/site directory in the repository root that you can verify locally.

Adding examples

To make sure examples are correct, we put examples in test files so they can be run as part of our test suites.

You can see the tests are at:

  • Python: python/python/tests/docs
  • Typescript: nodejs/examples/

Checking python examples

cd python
pytest -vv python/tests/docs

Checking typescript examples

The examples depend on @lancedb/lancedb at file:../dist, so the package must be built before running the tests. This uses pnpm; see the Typescript contributing guide for the toolchain setup.

pushd nodejs
pnpm install
pnpm build
popd

Then you can run the examples by going to the nodejs/examples directory, which is a separate pnpm package with its own lockfile:

pushd nodejs/examples
pnpm install
pnpm test
popd

API documentation

Python

The Python API documentation is organized based on the file docs/src/python/python.md. We manually add entries there so we can control the organization of the reference page. However, this means any new types must be manually added to the file. No additional steps are needed to generate the API documentation.

Typescript

The typescript API documentation is generated from the typescript source code using typedoc.

When new APIs are added, you must manually re-run the typedoc command to update the API documentation. The new files should be checked into the repository.

pushd nodejs
# `pnpm docs` would invoke pnpm's built-in `docs` command, not the script.
pnpm run docs
popd