morrySnow opened a new pull request, #59105:
URL: https://github.com/apache/doris/pull/59105
### What problem does this PR solve?
Related PR: #22203
Problem Summary:
This pull request refines the logic in the `EliminateEmptyRelation` rewrite
rule, focusing on how set operations (`UNION` and `EXCEPT`) handle empty
relations in query plans. The changes improve efficiency and code clarity by
processing only when necessary, optimizing builder usage, and simplifying
project and aggregate node construction.
**Set Operation Handling Improvements:**
* Updated the logic for `UNION` nodes to only process and eliminate empty
relation children when at least one is present, reducing unnecessary
computation. Builders are now initialized with expected sizes for efficiency,
and redundant code for handling constant expressions was removed.
* Improved handling of `EXCEPT` nodes by checking for empty relations only
among the right-hand children, and optimizing builder initialization. The
construction of aggregate and project nodes now uses the correct outputs
directly, streamlining the process.
### Release note
None
### Check List (For Author)
- Test <!-- At least one of them must be included. -->
- [ ] Regression test
- [ ] Unit Test
- [ ] Manual test (add detailed scripts or steps below)
- [ ] No need to test or manual test. Explain why:
- [ ] This is a refactor/code format and no logic has been changed.
- [ ] Previous test can cover this change.
- [ ] No code files have been changed.
- [ ] Other reason <!-- Add your reason? -->
- Behavior changed:
- [ ] No.
- [ ] Yes. <!-- Explain the behavior change -->
- Does this need documentation?
- [ ] No.
- [ ] Yes. <!-- Add document PR link here. eg:
https://github.com/apache/doris-website/pull/1214 -->
### Check List (For Reviewer who merge this PR)
- [ ] Confirm the release note
- [ ] Confirm test cases
- [ ] Confirm document
- [ ] Add branch pick label <!-- Add branch pick label that this PR should
merge into -->
--
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]
