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Posted to issues@calcite.apache.org by "Laurent Goujon (JIRA)" <ji...@apache.org> on 2019/01/25 19:11:00 UTC

[jira] [Updated] (CALCITE-2803) Identify expanded IS NOT DISTINCT FROM expression when pushing project past join

     [ https://issues.apache.org/jira/browse/CALCITE-2803?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Laurent Goujon updated CALCITE-2803:
------------------------------------
    Description: 
{{IS NOT DISTINCT FROM}} expressions in join condition might actually be considered as equi-join conditions, and {{RelOptUtil#splitJoinConditions()}} has support for it. But some other join related functions/rules don't.

One of them is {{ProjectJoinTransposeRule}} which tries to push project expressions below the join, but ends up modifying the join expression too by pushing complex expression below.

For example expression {{OR(AND(IS_NULL($1), IS_NULL($4)), EQUALS($1,$4))}} will be changed into {{OR(AND($3, $6), EQUALS($1, $5))}} which makes it harder/impossible for {{RelOptUtil#splitJoinConditions()}} to identify an {{IS NOT DISTINCT FROM}} equi-join condition.

  was:
{{IS NOT DISTINCT FROM}} expressions in join condition might actually be considered as equi-join conditions, and {{RelOptUtil#splitJoinConditions()}} has support for it. But some other join related functions/rules don't.

One of them is {{ProjectJoinTransposeRule}} which tries to push project expressions below the join, but ends up modifying the join expression too by pushing complex expression below/

For example expression {{OR(AND(IS_NULL($1), IS_NULL($4)), EQUALS($1,$4))}} will be changed into {{OR(AND($3, $6), EQUALS($1, $5))}} which makes it harder/impossible for {{RelOptUtil#splitJoinConditions()}} to identify an {{IS NOT DISTINCT FROM}} equi-join condition.


> Identify expanded IS NOT DISTINCT FROM expression when pushing project past join
> --------------------------------------------------------------------------------
>
>                 Key: CALCITE-2803
>                 URL: https://issues.apache.org/jira/browse/CALCITE-2803
>             Project: Calcite
>          Issue Type: Improvement
>          Components: core
>            Reporter: Laurent Goujon
>            Assignee: Julian Hyde
>            Priority: Major
>
> {{IS NOT DISTINCT FROM}} expressions in join condition might actually be considered as equi-join conditions, and {{RelOptUtil#splitJoinConditions()}} has support for it. But some other join related functions/rules don't.
> One of them is {{ProjectJoinTransposeRule}} which tries to push project expressions below the join, but ends up modifying the join expression too by pushing complex expression below.
> For example expression {{OR(AND(IS_NULL($1), IS_NULL($4)), EQUALS($1,$4))}} will be changed into {{OR(AND($3, $6), EQUALS($1, $5))}} which makes it harder/impossible for {{RelOptUtil#splitJoinConditions()}} to identify an {{IS NOT DISTINCT FROM}} equi-join condition.



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