[SPARK-39172] Remove outer join if all output come from streamed side and buffered side keys exist unique key

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: SQL
• Assignee: XiDuo You
• Reporter: XiDuo You
• Created: 13/May/22 02:57
• Updated: 16/May/22 17:08
• Resolved: 16/May/22 17:08

Description

Improve the optimzation case using the distinct keys framework.

For example:

SELECT t1.* FROM t1 LEFT JOIN (SELECT distinct c1 as c1 FROM t)t2 ON t1.c1 = t2.c1
==>
SELECT t1.* FROM t1 

Issue Links

• links to: [Github] Pull Request #36530 (ulysses-you)