Drew Gallardo
3dd9c598e9
## Summary - Implements Cloud `fetch_blob_files`: returns real seekable `BlobFile` handles over HTTP Range instead of `NotSupported`. - Completes the second Cloud blob read verb after #3684 (`fetch_blobs` = eager whole bytes; this = lazy / partial / sequential reads). - Same public handle API as local (`read_range`, `read_up_to`, `seek`, `tell`, `close`), so one code path works for local and Cloud. Large blobs (video, audio, PDFs) should not require downloading the whole object to inspect a header or stream a slice. After search, callers open a handle and read only what they need: ```python hits = table.search(vec).select(["id", "video"]).limit(5).to_arrow() with table.fetch_blob_files("video", hits)[0] as f: header = f.read_range(0, 256) f.seek(keyframe_offset) chunk = f.read_up_to(1 << 20) ``` ### Behavior - Handle creation probes size with `bytes=0-0` (bounded concurrency, input order preserved). - `204` → null (`None`); `416` with `bytes */0` → valid empty blob; other `416` → error. - `read_range` validates `Content-Range` and body length; OOB ranges fail with `invalid_input` before the request (aligned with Lance). - `read_up_to` reuses one open-ended Range response across sequential reads; `seek` drops it. - Servers older than 0.5.0 get a clear `NotSupported` (does not suggest `fetch_blobs`, which they also lack). ## Testing - `cargo test --features remote -p lancedb remote_blob` - `cargo test --features remote -p lancedb test_blob` - `cargo clippy --features remote --tests --examples` (no new warnings from this change) --------- Co-authored-by: Claude Fable 5 <noreply@anthropic.com> Co-authored-by: Cursor <cursoragent@cursor.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.