v.22.9Improvement

Disable Projection in Grouping Set to Fix Incorrect Results

Official CH changelog text
Disable projection when grouping set is used. It generated wrong result. This fixes #40635. #40726 (Amos Bird).
Disable projection optimization when GROUPING SET is used to avoid incorrect query results.

Why it matters

The feature addresses an issue where applying projection optimizations during queries with GROUPING SET caused incorrect result generation. Disabling projections for such queries ensures accurate aggregation results, improving correctness and reliability.

How to use it

This fix is applied automatically in ClickHouse starting from the version including this change. Users do not need to take any manual action; the system disables projections internally when processing queries with GROUPING SET.

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