[CALCITE-4225] Make RelDecorrelator pluggable

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.25.0
• Fix Version/s: 1.27.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Danny Chen
• Reporter: Danny Chen
• Created: 03/Sep/20 09:45
• Updated: 03/Jun/21 22:31
• Resolved: 26/Oct/20 07:54

Description

RelDecorrelator is our core component that decorrelates the queries. But actually, the pattern it can decorrelate successfully is very limited. And it often causes bug because it decorrelates into a wrong plan (with non-correct sementics).

When there are bugs there, the downstream project can only wait for the version upgrade (if it is fixed in Calcite master), or they copy the whole Java class and override the Calcite one which is hard to maintain.

It would be nice if we can make the decorrelation logic pluggable. e.g. we can control how a RelNode was decorrelated(not a coarse-grained flag to turn-on/off the decorrelation).

Issue Links

• links to: GitHub Pull Request #2228