Yang Cen
9dc5ec03aa
## What changed - add `block_size` to Python FTS configuration and the deprecated local/remote helpers - add `blockSize` to the TypeScript FTS options and propagate it through the NAPI binding - serialize the value as `block_size` for remote index creation - document the existing Rust builder API and generate the TypeScript API reference - add local, remote, metadata, search, and invalid-value regression coverage ## Why Lance supports configuring the number of documents per compressed FTS posting block, but LanceDB's Python and TypeScript APIs did not expose the setting. This made the experimental FTS V3 layout unavailable through those clients and allowed the value to be dropped before index creation. ## How it works The default remains `128`. Supported values are `128` and `256`; selecting `256` uses the experimental FTS V3 format. Invalid values are rejected by the Lance builder and surfaced as Python or JavaScript errors. ## Validation - `cargo check --quiet --features remote --tests --examples` - `cargo +1.94.0 clippy --quiet --features remote --tests --examples -- -D warnings` - targeted Rust local and remote index tests - Rust doctests: 34 passed - Python Ruff checks, doctest, and targeted local/remote tests: 5 passed - TypeScript build, Biome lint, generated docs, and targeted Jest tests: 9 passed - `git diff --check` ## Limitations The Java client remains unchanged because its external remote REST model does not currently expose `block_size`. Co-authored-by: Yang Cen <yangcen@Yangs-Mac-mini.local>
LanceDB Python SDK
A Python library for LanceDB.
Installation
pip install lancedb
Pre-Haswell x86_64 hosts: lancedb-compat
The default lancedb wheel targets x86-64-haswell (AVX2 + FMA + F16C) for full performance on modern hardware. Pre-Haswell hosts — Intel Sandy Bridge / Ivy Bridge / Westmere; AMD Bulldozer / Piledriver / Steamroller — don't have AVX2 and crash with Illegal instruction at import lancedb.
For those hosts, install the lancedb-compat package instead:
pip install lancedb-compat
Same Python API (import lancedb works as usual). The compat wheel is compiled at the x86-64-v2 baseline (Nehalem-class) and uses runtime SIMD dispatch in the embedded lance crate to pick the right kernel tier (scalar / AVX / AVX+FMA / AVX2+FMA / AVX-512) at load time, so it still goes fast on modern hardware while running cleanly on the pre-Haswell silicon. Use lance.simd_info() from Python to verify which tier was selected.
lancedb and lancedb-compat install to the same lancedb/ namespace and conflict at install time. Pick one. To switch, pip uninstall lancedb first, then pip install lancedb-compat (or vice-versa).
If you need a custom baseline (or lancedb-compat isn't yet published for your platform), build from source with the override:
RUSTFLAGS="-C target-cpu=x86-64-v2" maturin build --release
pip install ./target/wheels/lancedb-*.whl
Preview Releases
Stable releases are created about every 2 weeks. For the latest features and bug fixes, you can install the preview release. These releases receive the same level of testing as stable releases, but are not guaranteed to be available for more than 6 months after they are released. Once your application is stable, we recommend switching to stable releases.
pip install --pre --extra-index-url https://pypi.fury.io/lancedb/ lancedb
Usage
Basic Example
import lancedb
db = lancedb.connect('<PATH_TO_LANCEDB_DATASET>')
table = db.open_table('my_table')
results = table.search([0.1, 0.3]).limit(20).to_list()
print(results)
Development
See CONTRIBUTING.md for information on how to contribute to LanceDB.