DarvenDuan opened a new pull request, #28886: URL: https://github.com/apache/doris/pull/28886
If the `case when` contains a constant zero/null in SUM agg function, we can use preaggregation to speed up queries and it will not effect the correctness of result. Issue Number: close #xxx If we use `case when` or `if` in `SUM`, Planner will get the follows steps: 1、rewrite expression `if` to `case when`. 2、check the Index contains all key columns in `when` expr. 3、check the expr in `then` is constant zero/null. 4、check the expr in `else` is constant zero/null. If conditions 2, 3, and 3 are all met, we open preagg. ## Further comments If this is a relatively large or complex change, kick off the discussion at [[email protected]](mailto:[email protected]) by explaining why you chose the solution you did and what alternatives you considered, etc... -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
