lancedb-gatefixer[bot]
061a3da8b9
<!-- lance-gatekeeper-fix:v1 agent=40e5cf476a59265c71653574eda834d2 generation=1 --> ## Summary - preserve incoming PyArrow `arrow.json` fields while schema sanitization aligns input to a stored `lance.json` schema - let Lance perform the required JSONB encoding instead of relabeling raw JSON bytes as encoded storage - cover both merge insert and the conditional add sanitization path with end-to-end regression tests ## Root cause Python schema sanitization aligns incoming data to the table schema before passing it to Lance. Merge insert always takes this path, while add takes it conditionally for preprocessing such as non-default bad-vector handling or embedding functions. For JSON columns, the cast changed logical `arrow.json` strings into the table's JSONB-backed `lance.json` storage type without encoding the bytes, so Lance treated raw JSON text as JSONB. ## Validation - `cd python && uv run --extra tests pytest python/tests/test_table.py -k 'merge_insert or add_sanitization_encodes_json' -q` - targeted schema-cast and JSON encoding tests - `ruff check .` - `ruff format --check python/python/lancedb/table.py python/python/tests/test_table.py` Fixes #3923 --------- 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.