[SPARK-37455] Replace hash with sort aggregate if child is already sorted

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.3.0
• Fix Version/s: 3.3.0
• Component/s: SQL
• Assignee: Cheng Su
• Reporter: Cheng Su
• Created: 24/Nov/21 23:41
• Updated: 03/Dec/21 13:17
• Resolved: 03/Dec/21 13:17

Description

In the query plan, if the child of hash aggregate is already sorted on group-by columns, we can replace hash aggregate with sort aggregate for better performance, as sort aggregate does not have hashing overhead of hash aggregate.

Issue Links

• links to: [Github] Pull Request #34702 (c21)