[teiid-issues] [JBoss JIRA] (TEIID-5375) limit pushing should be considered prior to dependent join planning

[Steven Hawkins (JIRA)]

     [ https://issues.jboss.org/browse/TEIID-5375?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Steven Hawkins reassigned TEIID-5375:
-------------------------------------

    Fix Version/s: 11.x
                       (was: 11.0)
         Priority: Minor  (was: Major)
         Assignee:     (was: Steven Hawkins)


An example query:

select pm1.g1.e1, pm2.g1.e2 from pm1.g1 left outer join pm2.g1 on pm1.g1.e1 = pm2.g1.e1 limit 10

There isn't a great way to do this with the current logic as rule push limit will move the limit nodes into locations in the plan where they are not expected by other rules.  The other approach is to attempt to adjust the costing logic to look up in the tree, but that would largely need to duplicate the checks in rule push limit.  Moving out of 11.0.

> limit pushing should be considered prior to dependent join planning
> -------------------------------------------------------------------
>
>                 Key: TEIID-5375
>                 URL: https://issues.jboss.org/browse/TEIID-5375
>             Project: Teiid
>          Issue Type: Quality Risk
>          Components: Query Engine
>            Reporter: Steven Hawkins
>            Priority: Minor
>             Fix For: 11.x
>
>
> In some situations such as a limit over a left outer join, the effect of the limit should be considered in the costing of the left hand side of the join - but is currently not since rule push limits is fired after rule choose dependent.



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