[FLINK-30242] Push localHashAggregate pass the union node

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: Table SQL / Planner
• Labels: auto-deprioritized-major pull-request-available
• Assignee: Unassigned
• Reporter: WenJun Min
• Created: 30/Nov/22 06:18
• Updated: 20/Aug/23 10:35

Description

The local hash aggregate after union will have an extra shuffle stage. We can swap it with the union node so the local hash aggregate can chain with the mapper stage saving the unnecessary shuffle, especially in the batch job.

Issue Links

• links to: GitHub Pull Request #22001