[
https://issues.apache.org/jira/browse/CALCITE-3373?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17931797#comment-17931797
]
Viggo Chen commented on CALCITE-3373:
-------------------------------------
This graph shows how a SubQuery can be converted to a SemiJoin right now.
Modifying the existing SubQueryRemoveRule, SemiJoinRule, and RelDecorrelator
might cause incompatibilities with current behaviors, and not all engines
support SemiJoin, so I prefer to add a new rule for users who need it.
!image-2025-03-02-17-04-54-608.png!
> Decorrelate boolean context IN or existential subquery directly into
> SEMI/ANTI join
> -----------------------------------------------------------------------------------
>
> Key: CALCITE-3373
> URL: https://issues.apache.org/jira/browse/CALCITE-3373
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Reporter: Jin Xing
> Priority: Major
> Attachments: image-2025-03-02-17-00-48-325.png,
> image-2025-03-02-17-04-54-608.png
>
>
> The current approach to generate semi-join from IN/EXISTS is as below:
> # Decorrelation
> # Transforming by SemiJoinRule to get a semi-join
> A more straightforward approach is to generate the semi-join right in
> Decorrelation.
> What's more, we should also have an approach to generate anti-join right in
> Decorrelation.(Currently there's no analogous rule to SemiJoinRule for
> anti-join)
> This one is related to CALCITE-3367
>
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
