mustafasrepo commented on PR #9009: URL: https://github.com/apache/arrow-datafusion/pull/9009#issuecomment-1914173891
> Thank you for this contribution @mustafasrepo -- this PR looks good to me. Also, I found the description on this PR very clear and well written. Thank you very much 🙏 > > One thought I had was will there be a problem if there is a subquery that would end up with a nested WindowAggExec that could be incorrectly optimized away 🤔 > > Something like > > ```sql > SELECT c3, > SUM(c9) OVER(ORDER BY c3+c4 ASC) as sum2, > sum1, > FROM ( > SELECT c3, c4, c9, > SUM(c9) OVER(ORDER BY c3+c4 DESC) as sum1, > FROM aggregate_test_100 > ) > ``` I think, in these cases, we will generate a sub-optimal plan, where a complex expression is calculated more than once by subsequent operators. However, didn't cached (Previous behaviour). However, I don't think we will generate an invalid plan. I added your example as a test case also in this PR. I think as a future PR, we can analyze plan from top down to count expression referral count, for better calculating referral counts across plan. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
