[teiid-issues] [JBoss JIRA] (TEIID-5420) Costing can over estimate join cardinality when no keys nor ndv is specified

[Steven Hawkins (JIRA)]

     [ https://issues.jboss.org/browse/TEIID-5420?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Steven Hawkins resolved TEIID-5420.
-----------------------------------
    Resolution: Done


Changed to a simpler assumption to use high ndv for the side of the join that is more unique.

> Costing can over estimate join cardinality when no keys nor ndv is specified
> ----------------------------------------------------------------------------
>
>                 Key: TEIID-5420
>                 URL: https://issues.jboss.org/browse/TEIID-5420
>             Project: Teiid
>          Issue Type: Quality Risk
>          Components: Query Engine
>            Reporter: Steven Hawkins
>            Assignee: Steven Hawkins
>             Fix For: 11.1, 11.0.1
>
>
> The changes from TEIID-4885 allow for joins lacking all but cardinality information to have their cardinality over-estimated.  The estimate should be made more cautious by default as that would be the most common case.



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