Files
lancedb/python
lancedb-gatefixer[bot] b20696ef9c fix(remote): validate cloud DNS hostnames (#3845)
## Summary

- validate the generated LanceDB Cloud hostname during connection setup
- return a clear invalid-input error for empty, overlong, or oversized
DNS names before network resolution
- add Rust and Python regression coverage for malformed `db://`
authorities

## Root cause

The `db://` authority and region were interpolated into the Cloud API
hostname without DNS length validation. Empty or overlong labels
therefore reached the resolver and surfaced as an opaque IDNA
`UnicodeError` instead of a useful connection error.

## Validation

- `cargo test --quiet --features remote -p lancedb
test_rejects_invalid_cloud_dns_hostname --lib`
- `cargo check --quiet --features remote --tests --examples`
- `uv run --no-sync --extra tests pytest
python/tests/test_remote_db.py::test_async_remote_db
python/tests/test_remote_db.py::test_connect_rejects_invalid_cloud_dns_hostname
-q`
- `cargo fmt --all -- --check`
- `ruff check .`
- `ruff format --check python/python/tests/test_remote_db.py`

Fixes #799

<!-- lance-gatekeeper-fix:v1 agent=4d1597b3d244b58f0603ed40a8a59cf9
generation=1 -->

Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
2026-08-06 16:48:56 +08:00
..
2025-01-29 08:27:07 -08:00
2024-04-05 16:22:59 -07:00

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.