feat: join selectivity - Githubissues

cmu-db / optd

CMU-DB's Cascades optimizer framework

https://cmu-db.github.io/optd/

MIT License

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feat: join selectivity #145

Closed wangpatrick57 closed 7 months ago

wangpatrick57 commented 7 months ago

Summary: Implemented join selectivity formulas for inner joins, left/right outer joins, and cross joins. Also properly accounts for filters in the join condition.

Demo: We now match Postgres on our median Q-error. See #127 for more details on what queries this PR affected. Screenshot 2024-03-31 at 13 13 48

Details:

We only consider equality checks on columns of different tables to be "join on conditions".
Join selectivity formulas are from Rogov 2022.
If there are multiple on conditions, we multiply their selectivities together.