lance-format / lance-format/lance

Support update with blob encoding column

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A-encoding enhancement
Dominant language
Rust
Stars
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Forks
852
Avg merge
3d 18h
Merged PRs (30d)
272

Description

from discord

in rust/lance/src/dataset/write/update.rs:269-291:

  1. The update operation creates a scanner with default blob handling (BlobsDescriptions)
  2. With this default, blob columns (marked with lance-encoding:blob) are read as descriptions (Struct with position, size)
  3. The schema validation at line 286 compares the stream schema (with Struct) against the dataset schema (with LargeBinary)
  4. This causes a schema mismatch error

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Research direction

Start in rust/lance/src/dataset/write/update.rs:269-291 and trace how the update operation creates its scanner and validates the stream schema at line 286. Verify how blob columns marked with lance-encoding:blob are represented during the update, then confirm that an update no longer reports a mismatch between blob descriptions and LargeBinary dataset columns.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
data-engineering
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
48/100

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