Major Description
The Sort without Limit operator in Join/GroupBy subquery is useless.
For example, select count(1) from (select a from test1 order by a) is equal to select count(1) from (select a from test1).
'select * from (select a from test1 order by a) t1 join (select b from test2) t2 on t1.a = t2.b' is equal to select * from (select a from test1) t1 join (select b from test2) t2 on t1.a = t2.b.
Remove useless Sort operator can import performance.
Attachments
Issue Links
- is duplicated by
-
SPARK-27290 remove unneed sort under Aggregate
-
- Open
-
- links to
