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4c44587af0
Fixes #3183 ## Summary When `table.add(mode='overwrite')` is called, PyArrow infers input data types (e.g. `list<double>`) which differ from the original table schema (e.g. `fixed_size_list<float32>`). Previously, overwrite mode bypassed `cast_to_table_schema()` entirely, so the inferred types replaced the original schema, breaking vector search. This fix builds a merged target schema for overwrite: columns present in the existing table schema keep their original types, while columns unique to the input pass through as-is. This way `cast_to_table_schema()` is applied unconditionally, preserving vector column types without blocking schema evolution. ## Changes - `rust/lancedb/src/table/add_data.rs`: For overwrite mode, construct a target schema by matching input columns against the existing table schema, then cast. Non-overwrite (append) path is unchanged. - Added `test_add_overwrite_preserves_vector_type` test that creates a table with `fixed_size_list<float32>`, overwrites with `list<double>` input, and asserts the original type is preserved. ## Test Plan - `cargo test --features remote -p lancedb -- test_add_overwrite` — all 4 overwrite tests pass - Full suite: 454 passed, 2 failed (pre-existing `remote::retry` flakes unrelated to this change) --------- Signed-off-by: majiayu000 <1835304752@qq.com>
LanceDB Python SDK
A Python library for LanceDB.
Installation
pip install lancedb
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.