ygf11 opened a new pull request, #5345:
URL: https://github.com/apache/arrow-datafusion/pull/5345
# Which issue does this PR close?
<!--
We generally require a GitHub issue to be filed for all bug fixes and
enhancements and this helps us generate change logs for our releases. You can
link an issue to this PR using the GitHub syntax. For example `Closes #123`
indicates that this PR will close issue #123.
-->
Closes #5344.
# Rationale for this change
<!--
Why are you proposing this change? If this is already explained clearly in
the issue then this section is not needed.
Explaining clearly why changes are proposed helps reviewers understand your
changes and offer better suggestions for fixes.
-->
In #5264, we support rewriting more `where-exists` to join, but do not add
back the `Distinct`.
For query:
```sql
SELECT t1.t1_id
FROM t1
WHERE EXISTS(SELECT DISTINCT t2_int
FROM t2
WHERE t2.t2_id > t1.t1_id);
// current logical plan:
Projection: t1.t1_id
LeftSemi Join: Filter: t2.t2_id > t1.t1_id
TableScan: t1 projection=[t1_id]
Projection: t2.t2_id
TableScan: t2 projection=[t2_id]
```
Although the execution result is correct, we should add back the `DISTINCT`.
In some cases, `DISTINCT` can filter a lot rows before join, we should let
`user` choose.
# What changes are included in this PR?
<!--
There is no need to duplicate the description in the issue here but it is
sometimes worth providing a summary of the individual changes in this PR.
-->
Refactor `optimize_exists` and add `optimize_subquery`.
# Are these changes tested?
<!--
We typically require tests for all PRs in order to:
1. Prevent the code from being accidentally broken by subsequent changes
2. Serve as another way to document the expected behavior of the code
If tests are not included in your PR, please explain why (for example, are
they covered by existing tests)?
-->
# Are there any user-facing changes?
<!--
If there are user-facing changes then we may require documentation to be
updated before approving the PR.
-->
<!--
If there are any breaking changes to public APIs, please add the `api
change` label.
-->
--
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]
