SQL blob descriptors need pinned source identity to reopen a value after
the query finishes. Adds `open_blob_file(descriptor)` and
`open_blob_files(descriptors)` so Python can read the original blob
incrementally without materializing it in the SQL result.
### Python experience
```python
rows = db.execute_query("""
SELECT f.timestamp, blob_descriptor(v.video) AS video
FROM videos v JOIN frames f ON v.id = f.video_id
""").read_all()
videos = db.open_table("videos")
for row in rows.to_pylist():
if row["video"] is not None:
with videos.open_blob_file(row["video"]) as video:
frame = extract_frame(video, row["timestamp"])
```
The singular API accepts the descriptor dictionary or an Arrow struct
scalar directly and returns a seekable `BlobFile`.
`videos.open_blob_files(rows["video"])` accepts an Arrow array/chunked
array or another iterable, opens handles as iteration advances, and
preserves order, duplicates, and nulls as `None`. Async tables provide
`await videos.open_blob_file(...)` and `async for video in
videos.open_blob_files(...)`.
The iterable API can be used directly with the Arrow result column. Zip
it with the rows to keep each frame timestamp:
```python
for row, video in zip(rows.to_pylist(), videos.open_blob_files(rows["video"])):
if video is not None:
with video:
frame = extract_frame(video, row["timestamp"])
```
Each iteration opens one handle. Null descriptors yield `None`; handles
preserve input order and duplicates, and the `with` block closes each
non-null file.
For an async table:
```python
async for video in async_videos.open_blob_files(rows["video"]):
if video is not None:
with video:
payload = await video.aread()
```
### Execution
The descriptor retains the canonical `kind`, `position`, `size`,
`blob_id`, and `blob_uri` fields and carries a `source` struct with its
dataset URI, version, commit timestamp, branch, column, row reference,
and whether that reference is a physical address. Native opening
resolves that exact snapshot without changing the table handle's
checkout and rejects a descriptor belonging to another table. Remote
handles send authenticated byte-range requests with the captured
version/branch, commit timestamp, and source URI, so an old physical
address is never interpreted against the latest table.
Known-size remote descriptors open without a payload request. External
blobs with an unspecified size use a metadata-only HEAD request. Payload
bytes load only when the file is read; full reads still allocate the
full value. Existing row-ID-based `fetch_blob_files` remains available
when a descriptor is not already present.
Coverage includes native snapshot preservation after overwrite, both row
IDs and addresses, dictionary/Arrow inputs, null/empty values, reordered
and duplicate descriptors, lazy iterable behavior, async iteration, and
remote range pinning for all six storage kinds.
Descriptor reads isolate their pinned snapshot from the live table
handle's freshness state. Both native and remote reads verify the source
commit timestamp to reject a replaced snapshot after table recreation.
Fixes#4248.
The preview index still contains pylance 1.0.0b6. uv's default
first-index resolution can select it, or backtrack to an old LanceDB
release when installing the extra. Meanwhile, the extra still permits
pylance 5 even though current main bundles Lance 14.
Raise the optional dependency to `pylance>=14.0.0b12`, the version
already pinned in the test extra, and keep the lockfile metadata
consistent. Document both Fury indexes and uv's `unsafe-best-match`
strategy in the Python README and the source-owned quickstart
(`docs/web/quickstart.mdx`). Explain the index trust requirement and
recommend installing the extra to enforce the version floor.
Add CI checks that reject older Lance majors and ensure the pylance and
tests extras remain compatible. Run these checks when either dependency
manifest changes, so a future Lance major bump cannot silently leave the
Python minimum behind.
### Validation
- Recreated the reported install on Ubuntu 26.04 / CPython 3.12.15 with
uv 0.12.23: `lancedb==0.40.0b5` plus the old index selects
`pylance==1.0.0b6`. Reproduced both the missing `blob_array` import and
the unexpected `blob_handling` scanner argument using a real blob table.
- Resolved the modified `python/pyproject.toml` with the pylance extra
against both indexes: selects `pylance==14.0.0b18`, matching the current
Rust pin.
- Ran both documented pip and uv installations in isolated environments:
`lancedb==0.41.0b7`, `pylance==14.0.0b18`; blob-array construction and a
blob-bytes round trip through `to_pandas(blob_mode="bytes")` pass. Both
package dependency checks pass.
- New regression fails on the original dependency bound (27
rejected-version cases incorrectly accepted), then passes with the fix.
Full CI-script suite: 3 tests pass.
- `uv lock --check` with both indexes passes; focused Ruff checks pass;
`git diff --check` passes.
- Repository-wide Ruff reports 49 existing errors in untouched
`docs/web-tests` files. Unrelated formatting changes were discarded.
Runtime smoke checks used released native wheels; source dependency
resolution was tested directly from the modified pyproject. No Rust or
Python runtime code changes.
---------
Co-authored-by: Xuanwo <github@xuanwo.io>
Closes#4246.
lancedb publishes no source distribution, so a platform without a
prebuilt wheel (#4104, #4239) has nothing to install. This adds an sdist
to the Python release.
## The sdist job
The release workflow builds an sdist with the maturin version of the
wheel jobs. On a tag, the publish job uploads it with the wheels: to
PyPI, and to Fury for beta tags. The job also runs on the pull request
dry run, which now starts on a change to `python/pyproject.toml`.
## Checks
- The job builds a wheel from the sdist with `--locked` and smoke-tests
it in a fresh venv.
- `ci/check_sdist.py` fails if a tracked file of the Python package is
missing from the tarball.
- `twine check --strict` checks that the metadata renders. `pydistcheck`
enforces PyPI's 100 MiB size limit.
- The unit tests of both check scripts run in the CI scripts workflow.
## Cargo.lock
maturin ships the repository lockfile, which pins crates that only the
dropped `nodejs` member uses, so `cargo --locked` fails
(PyO3/maturin#2609). The job first runs `cargo metadata --locked` on the
repository workspace, so a lockfile that has drifted from `Cargo.toml`
fails there. It then removes the nodejs-only pins and repacks the sdist.
`ci/check_cargo_lock.py` fails if the prune changes any package it
keeps, or any dependency of one. The published file is the repacked one.
## Behavior change
After the first release with an sdist, pip on a platform with no current
wheel builds the newest version from source, which needs a Rust
toolchain and `protoc`. Before, pip installed the last version with a
wheel for that platform.
## Summary
- document that current LanceDB releases use one compute worker without
warning on two-vCPU containers
- distinguish compute-worker tuning from storage I/O concurrency
- direct users of affected LanceDB 0.21.1 installations to upgrade and
link the current threading guidance
## Root cause
The Lance version bundled with LanceDB 0.21.1 warned whenever the
detected CPU count was less than or equal to its default two-core I/O
reservation. A two-vCPU deployment therefore emitted the warning on
every query even though falling back to one compute worker was the
intended behavior. Lance fixed that warning condition upstream in
lance-format/lance#3710, and LanceDB current main already pins a version
containing the runtime fix; the Python package documentation did not
explain the corrected behavior or the distinct thread controls.
## Validation
- `git diff --check`
- verified the linked Lance threading-model documentation returns HTTP
200
Fixes#2326
<!-- lance-gatekeeper-fix:v1 agent=9f141242416a6dbeb43be0e80404dd4d
generation=1 -->
Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
Tracks #3324. On x86_64 CPUs without AVX2 (Sandy Bridge / Ivy Bridge /
Westmere on Intel; Bulldozer / Piledriver / Steamroller on AMD), `import
lancedb` SIGILLs because the wheel bakes AVX2 + FMA into every compiled
function. Per [westonpace's
review](https://github.com/lancedb/lancedb/issues/3324#issuecomment-4328944354),
the default `lancedb` wheel stays fast; pre-Haswell users get a
separately-published `lancedb-compat` wheel.
## Summary
- Adds a `lancedb-compat` matrix entry to `pypi-publish.yml` that builds
with `RUSTFLAGS="-C target-cpu=x86-64-v2"` (Nehalem-class baseline).
Same Python API (`import lancedb` works) — files install to the same
namespace, so the two wheels conflict at install time and users pick
one. Same pattern as `psycopg2` / `psycopg2-binary` and `tensorflow` /
`tensorflow-cpu`.
- Generalizes `build_linux_wheel` and `upload_wheel` composites with
optional `package-name` and `rustflags` inputs (defaults preserve the
existing 4 `lancedb` matrix entries verbatim).
- Documents the choice in `python/README.md`: `pip install
lancedb-compat` for pre-Haswell hosts.
The default `.cargo/config.toml` baseline is unchanged.
## Sequencing
1. ~~lance-format/lance#6630 merges → runtime SIMD dispatch lands in
lance.~~ **Done — merged.**
2. lancedb's lance dep is bumped to a release that includes it (separate
PR / normal cadence).
3. This PR's `lancedb-compat` wheel build path starts producing a wheel
that runs on pre-Haswell hardware. **Maintainer setup**: register
`lancedb-compat` on PyPI and configure trusted publishing.
## Verified end-to-end on Sandy Bridge Xeon E5-2609
Verification was done locally against a fork-pinned lance dep that
includes the runtime dispatch implementation, using the same
`RUSTFLAGS="-C target-cpu=x86-64-v2"` flags this PR uses in CI:
```
$ RUSTFLAGS="-C target-cpu=x86-64-v2" maturin build --release
$ pip install ./target/wheels/lancedb-*.whl
$ python verify.py
PASS: import + simd dispatch + table create + vector search all work.
```
Pre-fix on the same CPU (default `pip install lancedb`): `Illegal
instruction (core dumped)`. Full reproducer (deps + clone + build +
verification):
https://gist.github.com/tobocop2/2e341358b55c143527416edfdb1e37df.
Fork-internal verification PR with the dep bump and full logs:
[`tobocop2/lancedb#2`](https://github.com/tobocop2/lancedb/pull/2).
## Benchmarks — no regressions on modern CPUs from the lance-side change
These are the numbers I ran for the lance PR, confirming the runtime
dispatch doesn't slow down the default (`target-cpu=haswell`) wheel that
existing users install. Criterion, one machine, one session, base → PR,
no `RUSTFLAGS` override. Full methodology, null experiments, and logs:
[lance-format/lance#6630 benchmark
comment](https://github.com/lance-format/lance/pull/6630#issuecomment-4933063394)
and the [logs
gist](https://gist.github.com/tobocop2/3c6d0f449cbd736aa2501f89a7fe56a2).
| benchmark | EPYC 7B13 (`avx2`, `fma`, no `avx512f`) | Xeon Cascade
Lake (`avx512f`) |
|---|---|---|
| `Cosine(f32, scalar)` *(control)* | +0.04% | +0.09% |
| `Cosine(f64, scalar)` | −0.34% | −1.94% |
| `Cosine(u8, SIMD)` | +2.30% | +3.63% |
| `Dot(f16, SIMD)` | −0.58% | +0.61% |
| `Dot(f32, SIMD)` | +0.34% | **−6.08%** |
| `Dot(f32, arrow_arity)` | +0.02% | −0.00% |
| `L2(f32, scalar)` | −0.10% | −0.02% |
| `L2(f32, simd)` (dim 1024) | +2.63% | −0.53% |
| **`L2(simd,f32x8)` (dim 8)** | **−45.9%** | **−25.1%** |
| `L2(u8, SIMD)` | +0.42% | −3.11% |
| `NormL2(f32, SIMD)` | −1.02% | −4.17% |
| `NormL2(f64, SIMD)` | +3.51% | −0.58% |
Nothing regresses beyond the noise floor. Dim 8 — the PQ sub-vector
width — improves 25–46%.
---
To be transparent: this isn't my domain of expertise and the lance-side
implementation is AI-generated. I verified it works end-to-end on the
failing hardware. Happy to roll in feedback.
Exposes `storage_options` in LanceDB. This is provided for Python async,
Node `lancedb`, and Node `vectordb` (and Rust of course). Python
synchronous is omitted because it's not compatible with the PyArrow
filesystems we use there currently. In the future, we will move the sync
API to wrap the async one, and then it will get support for
`storage_options`.
1. Fixes#1168
2. Closes#1165
3. Closes#1082
4. Closes#439
5. Closes#897
6. Closes#642
7. Closes#281
8. Closes#114
9. Closes#990
10. Deprecating `awsCredentials` and `awsRegion`. Users are encouraged
to use `storageOptions` instead.
This changes `lancedb` from a "pure python" setuptools project to a
maturin project and adds a rust lancedb dependency.
The async python client is extremely minimal (only `connect` and
`Connection.table_names` are supported). The purpose of this PR is to
get the infrastructure in place for building out the rest of the async
client.
Although this is not technically a breaking change (no APIs are
changing) it is still a considerable change in the way the wheels are
built because they now include the native shared library.
This PR refactors how we handle read consistency: does the `LanceTable`
class always pick up modifications to the table made by other instance
or processes. Users have three options they can set at the connection
level:
1. (Default) `read_consistency_interval=None` means it will not check at
all. Users can call `table.checkout_latest()` to manually check for
updates.
2. `read_consistency_interval=timedelta(0)` means **always** check for
updates, giving strong read consistency.
3. `read_consistency_interval=timedelta(seconds=20)` means check for
updates every 20 seconds. This is eventual consistency, a compromise
between the two options above.
There is now an explicit difference between a `LanceTable` that tracks
the current version and one that is fixed at a historical version. We
now enforce that users cannot write if they have checked out an old
version. They are instructed to call `checkout_latest()` before calling
the write methods.
Since `conn.open_table()` doesn't have a parameter for version, users
will only get fixed references if they call `table.checkout()`.
The difference between these two can be seen in the repr: Table that are
fixed at a particular version will have a `version` displayed in the
repr. Otherwise, the version will not be shown.
```python
>>> table
LanceTable(connection=..., name="my_table")
>>> table.checkout(1)
>>> table
LanceTable(connection=..., name="my_table", version=1)
```
I decided to not create different classes for these states, because I
think we already have enough complexity with the Cloud vs OSS table
references.
Based on #812
Add `to_list` to return query results as list of python dict (so we're
not too pandas-centric). Closes#555
Add `to_pandas` API and add deprecation warning on `to_df`. Closes#545
Co-authored-by: Chang She <chang@lancedb.com>
Jack Ye
KarthikSandXuanwo
Tobias
lancedb-gatefixer[bot]
Will Jones
Weston Pace
Lei Xu
Chang SheandChang She
Leon Yee