lance-format / lance-format/lance

Cache open fragments

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#2,422 1 comment 0 reactions 0 assignees View on GitHub

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performance rust
Dominant language
Rust
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Avg merge
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Merged PRs (30d)
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Description

For every query, we call FileFragment::open(), which does maybe does some IO, schema manipulation, and then retrieves stuff from the metadata cache. Those first two will be optimized in #2420 and #2421. But if we are re-opening often enough for the same version of a dataset, it's perhaps worth considering caching these handles.

The main wrinkle is that these handles hold pointers to other data that is in the file metadata cache, which may pose issues for eviction policies (double counting size, evicting wrong items, etc.).

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First steps

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  3. Fork the repository and make your change on a branch.
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Research direction

Start with FileFragment::open() and the metadata cache behavior described here, then review the related optimization work in #2420 and #2421. Define whether handles can be cached for repeated openings of the same dataset version while accounting for their pointers and cache eviction; done requires an agreed safe caching design.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
databases
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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