lancedb-gatefixer[bot]
c3176a47ce
## Summary - add Python regression coverage for an IVF build that cannot form all requested non-empty partitions - verify hierarchical k-means returns an actionable RuntimeError instead of panicking or silently creating a degenerate index - exercise the current Lance v10.1.0-beta.1 dependency, which contains the upstream error-return fix ## Root cause Hierarchical k-means previously guarded a shortfall in generated clusters with only a debug assertion. Debug builds panicked, while release builds could silently publish an index with many empty partitions. The upstream Lance fix now returns a descriptive error and is already included in the dependency pinned on main; this test locks in propagation through the LanceDB Python API. ## Validation - uv run --extra tests pytest python/tests/test_index.py -q (24 passed) - uv run --extra tests pytest python/tests/test_index.py::test_create_ivf_index_reports_unsplittable_partitions -q (1 passed) - python/.venv/bin/ruff format python/python/tests/test_index.py - python/.venv/bin/ruff check . - git diff --check Fixes #3649 <!-- lance-gatekeeper-fix:v1 agent=a4d34448a9d350a3e2e659f33f5db6f2 generation=1 --> Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
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.