[SPARK-34257] Improve performance for last_value over unbounded window frame

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 3.2.0
• Component/s: SQL
• Assignee: Unassigned
• Reporter: Jiaan Geng
• Created: 27/Jan/21 07:06
• Updated: 08/May/21 09:16
• Resolved: 31/Mar/21 15:18

Description

The current implement of `last_value` over unbounded window frame will execute `updateExpressions` multiple times.
In fact, `last_value` only execute `updateExpressions` once on the last row.

Issue Links

• links to: [Github] Pull Request #31356 (beliefer)
• links to: [Github] Pull Request #31356 (beliefer)