milanisvet commented on PR #49518:
URL: https://github.com/apache/spark/pull/49518#issuecomment-2609909537

   As discussed offline about subqueries:
   1. The bug in `CTESubstitution` that self-references within subqueries are 
not substituted is fixed now.
   2. We agreed that we don't want to resolve self-references within subqueries 
at all, therefore, we can not perform the check about this in `checkAnalysis`, 
but rather in `ResolveWithCTE`.
   3. More thorough explanation: check in `checkAnalysis` would require 
`union`->`unionLoop` substitution, so that we still have `cteId` even if the 
CTE is inlined. However, only substituting `union`->`unionLoop` and not 
`CTERelationRef`->`UnionLoopRef` would make the current `ResolveWithCTE` code 
behave as not intended. We don't want to perform second substitution as we 
agreed not to resolve self-references within subqueries
   


-- 
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.

To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org

Reply via email to