v.25.11Performance Improvement
Parallel Merge FOr Small Group By
When a query uses fixed hash map for aggregation state (group by a small integer), ClickHouse would merge the aggregation state in parallel to speed up the query. #87366 (Jianfei Hu).
When a query uses fixed hash map for aggregation state (group by a small integer), ClickHouse would merge the aggregation state in parallel to speed up the query. #87366 (Jianfei Hu).