lance-format / lance-format/lance

It is not obvious, from analyze_plan output, how many rows are covered by the index

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A-index enhancement
Dominant language
Rust
Stars
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Forks
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Avg merge
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Merged PRs (30d)
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Description

I was recently debugging a performance issue where the FilteredRead was very slow even though a scalar index was applied. It turns out the index was not updated (less than half the rows were covered by the index). It was not obvious from the analyze plan output that this was the problem and it should be something we can easily report.

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the analyze_plan implementation and the FilteredRead path that uses the scalar index. Inspect how the plan currently reports index information, then determine how to expose the number or proportion of rows covered; done means analyze_plan makes incomplete index coverage apparent.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
databases
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

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