Dan Rammer
cdebea118d
## Summary
The sync `RemoteTable` carried `set_lsm_write_spec`,
`unset_lsm_write_spec`, `get_lsm_write_spec`, and `close_lsm_writers`,
but not `checkpoint_lsm`, `flush_lsm`, `compact_lsm`, or
`get_lsm_stats`.
That left the four LSM control methods reachable from `AsyncTable` only.
They are also the four that *only* work against a remote table —
`NativeTable` does not override the `BaseTable` defaults, so on a local
table they return `NotSupported` (`rust/lancedb/src/table.rs:679-701`).
The net effect for sync users:
| | `checkpoint_lsm` / `get_lsm_stats` |
|---|---|
| `LanceTable` (sync, local) | present, but always `NotSupported` |
| `RemoteTable` (sync, remote) | `AttributeError` — method absent |
| `AsyncTable` (remote) | works |
So there was no working sync path at all, despite the Rust `RemoteTable`
implementing every one of these against real endpoints.
## Changes
* Add `checkpoint_lsm`, `flush_lsm`, `compact_lsm`, and `get_lsm_stats`
to `lancedb.remote.table.RemoteTable`, mirroring the delegation style of
their neighbours.
* Correct the docstrings on `set_lsm_write_spec` /
`unset_lsm_write_spec`, which read `"""Not supported on LanceDB
Cloud."""` although `rust/lancedb/src/remote/table.rs:2549-2601`
implements both against `/v1/table/{}/set_lsm_write_spec/` and
`/unset_lsm_write_spec/`. They appear to have been copy-pasted from
`set_unenforced_primary_key` directly above.
No Rust or PyO3 changes — the bindings and the `AsyncTable` methods
already existed. The `Table` ABC is left alone, matching how the
existing `*_lsm_write_spec` methods are declared on the concrete classes
only.
## Tests
Four new tests in `python/python/tests/test_remote_db.py`, against the
existing mock HTTP server:
* `test_get_lsm_stats_sync` — the server payload round-trips into the
dict, and `include_generation_rows` defaults to `False` and is forwarded
when set.
* `test_get_lsm_stats_sync_returns_none_when_lsm_disabled` — a
`{"lsm_stats": null}` envelope yields `None` rather than an error.
* `test_flush_and_compact_lsm_sync` — both are one-shot POSTs answered
`202` with no body.
* `test_checkpoint_lsm_sync` — pins the binding to the endpoints it
drives (`flush_lsm` then `get_lsm_stats`); the convergence loop itself
is already covered in Rust.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
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.