v.22.12New Feature

Add grace_hash JOIN algorithm support to ClickHouse

Official CH changelog text
Add grace_hash JOIN algorithm, it can be enabled with SET join_algorithm = 'grace_hash'. #38191 (BigRedEye, Vladimir C).
Introduced the grace_hash JOIN algorithm in ClickHouse, offering an alternative join method to improve query performance.

Why it matters

The grace_hash join algorithm addresses limitations in existing join methods by providing a more efficient join strategy for large datasets or specific workload patterns, enhancing query execution speed and resource utilization.

How to use it

Enable the new join algorithm by setting the join algorithm parameter in your query with:

SET join_algorithm = 'grace_hash'

This setting activates the grace_hash join for the duration of the session or query.

Related resources

PreviousNext