Rebuild projection for merges that reduce number of rows. #62364 (cangyin).
ClickHouse now supports rebuilding projections during merges that reduce the number of rows.
Why it matters
This feature ensures that projections remain accurate and up-to-date when merges in the data reduce the number of rows, thus maintaining query correctness and data consistency.
How to use it
Projections will be automatically rebuilt during merges that reduce rows without requiring additional user actions.