Daniel Rammer
a651b67c76
Four of the eight LSM methods are remote-only in the core: `impl BaseTable for NativeTable` implements only set/unset/get_lsm_write_spec and close_lsm_writers, while flush_lsm, compact_lsm and get_lsm_stats fall through to trait defaults returning NotSupported. That is why Node had bound the four that work locally and stopped, and why the remaining four had no binding-level coverage anywhere. Node: add napi bindings for flush_lsm, compact_lsm, checkpoint_lsm and get_lsm_stats, with typed LsmStats/BucketStats/GenerationStats/ MemtableStats objects mirroring the existing LsmWriteSpec object in the same file. Tests assert each binding reaches the core and surfaces NotSupported locally; behavior against a real endpoint stays covered by the mocked-endpoint tests in rust/lancedb/src/remote/table.rs. Python: LsmWriteSpec was importable only from the private lancedb._lancedb -- it appeared in table.py solely under `if TYPE_CHECKING:`. Export it as lancedb.LsmWriteSpec, add it to __all__, and list it in the API reference, which had no mention of it and so rendered it nowhere. Java: add the LSM routes to lancedb-core. Java reaches LanceDB purely over REST through the generated namespace client, and these routes are not in the Lance Namespace spec, so they are issued through a small dedicated client. LsmWriteSpec is deliberately not org.lance.memwal. InitializeMemWalParams: that type defaults to maintaining no indexes where a spec here defaults to maintaining every index, and it cannot express the null that asks the server to resolve the set. checkpointLsm is ported from rust/lancedb/src/table/checkpoint.rs with its constants and status semantics intact -- 429/503 retried in place, 421 restarting from flush. Note: `mvnw spotless:apply` cannot run on JDK 21 (google-java-format 1.7, pinned in java/pom.xml, predates JDK 16's compiler API change). This is pre-existing and reproduces on a pristine main checkout; the Java sources here were formatted by hand to the checkstyle rules. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.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.