Remote Blob reads retain and concatenate intermediate IPC buffers across batches and HTTP requests, increasing peak memory. Decode fragmented IPC bodies using their declared length, assemble Blob values once across batches/requests, and collect large-object Range responses into known-size buffers. Impossible IPC/Range allocations return errors instead of panicking. Closing a remote Blob file releases cached bytes immediately, including while a cross-window read is waiting for the network. Rust and Python expose configurable Blob read buffers. Python sync/async `fetch_blob_files` and `open_blob_file(s)` accept `buffer_size`; the default is 512 KiB and zero disables prefetch. Explicit ranges bypass prefetch. New PE batch-endpoint adoption is separate. Malformed-length and retained-cache regressions fail on the previous implementation and pass after the correction. Real HTTP tests cover buffer propagation, close during blocked input, batch/request aggregation, and large-object fallback. The final extension was rebuilt before Python validation. Non-Blob Arrow arrays may still require alignment copies; a contiguous multi-batch result still requires its final allocation. ## Benchmark Peak client RSS increment in KiB, using `python/benchmarks/bench_fetch_blobs_rss.py`, independent clients and real loopback HTTP. Both extensions were rebuilt from clean, unchanged source with the same toolchain/configuration; loaded artifact hashes were checked. Baseline `42f11d13a2755e44b63876b5a5edd93901291150`, after `0a8a76de5286949d80368f95a5c529adf422c187`. | Equivalent fetch workload | Payload | Before | After | | --- | ---: | ---: | ---: | | Single response, one batch | 48 MiB | 63,812 | 63,896 | | Multiple responses, one batch per response | 144 MiB | 423,104 | 195,628 | | Single response, 12 rows per batch | 48 MiB | 130,520 | 71,348 | | Multiple responses, 12 rows per batch | 144 MiB | 363,144 | 172,748 | | One oversized row, Range fallback | 70 MiB | 182,816 | 85,548 | These are one observation per workload and build, not a statistical distribution or memory upper bound. The single-batch workload shows no improvement. Cloud/Sophon deployment, credentialed S3 and long-running stress have not been exercised.
LanceDB Documentation
For website guides in docs/web, start with
Documentation in CONTRIBUTING.md. That
covers editing pages, generated examples, previews, availability and drafts.
This page covers the SDK reference in docs/src, built with MkDocs. Its
GitHub Actions workflow builds and deploys on
pushes to main, so it can include unreleased APIs. That is separate from the
release editions of the Mintlify website.
Building the docs
Setup
- Install LanceDB Python. See setup in Python contributing guide.
Run
make developto install the Python package. - 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