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Posted to issues@calcite.apache.org by "Chunwei Lei (JIRA)" <ji...@apache.org> on 2019/04/14 12:31:00 UTC
[jira] [Commented] (CALCITE-2997) Avoid pushing down join condition
in SqlToRelConverter
[ https://issues.apache.org/jira/browse/CALCITE-2997?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16817291#comment-16817291 ]
Chunwei Lei commented on CALCITE-2997:
--------------------------------------
I believe that the logical plan is right anyway. Why do you want to make sure logical plan is exactly corresponds to SqlNode?
> Avoid pushing down join condition in SqlToRelConverter
> ------------------------------------------------------
>
> Key: CALCITE-2997
> URL: https://issues.apache.org/jira/browse/CALCITE-2997
> Project: Calcite
> Issue Type: Bug
> Reporter: jin xing
> Priority: Major
>
> In current code, *SqlToRelConverter:createJoin* is calling *RelOptUtil.pushDownJoinConditions* for optimization. And we can find below conversion from *SqlNode* to *RelNode*:
> {code:java}
> SqlNode:
> select * from A join B on A.x = B.x * 2
> RelNode (Logical-Plan):
> Join (condition:col0=col1)
> |-Project(x as col0)
> | |-Scan(A)
> |-Project(x * 2 as col1)
> |-Scan(B){code}
> As we can see the logical plan(*RelNode*) posted above is not the pure reflection of the original SQL String(*SqlNode*). The optimization is mixed into the phase on which AST is converted to Logical-Plan. Actually optimizing rule of JoinPushExpressionsRule is doing exactly the same kind of thing. Shall we just keep the optimization inside Optimized-Logical-Plan ? I mean shall we avoid calling *RelOptUtil.pushDownJoinConditions* in *SqlToRelConverter:createJoin*
> I raised this issue because that we are doing something based on the Logical-Plan. And it makes us really confused that the Logical-Plan doesn't corresponds to SqlNode.
>
>
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