cloud-fan commented on issue #26437: [SPARK-29800][SQL] Plan Exists 's subquery 
in PlanSubqueries
URL: https://github.com/apache/spark/pull/26437#issuecomment-552319361
 
 
   some more thoughts: I think we can rewrite non-correlated EXISTS subquery to 
a non-correlated scalar subquery.
   
   e.g. `SELECT.. FROM t1 WHERE (SELECT ...)` can be converted to `SELECT ... 
FROM t1 WHERE (SELECT count(*) FROM (SELECT ...)) = 0`. Then we don't need to 
create a new expression.

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
[email protected]


With regards,
Apache Git Services

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to