v.22.10Improvement

Fix parallel parsing memory overallocation in segmentator

Fix parallel parsing: segmentator now checks max_block_size. This fixed memory overallocation in case of parallel parsing and small LIMIT. #41852 (Vitaly Baranov).
Fixed memory overallocation during parallel parsing by ensuring the segmentator respects the max_block_size setting.

Why it matters

This change addresses the issue where parallel parsing with a small LIMIT caused excessive memory usage due to the segmentator not checking the max_block_size parameter. By fixing this, memory consumption is optimized and controlled during query execution.

How to use it

Users benefit from this improvement automatically when running queries with parallel parsing enabled. No additional configuration is needed, but users should ensure max_block_size is set appropriately to control memory usage.