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https://issues.apache.org/jira/browse/TRAFODION-1669?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15038611#comment-15038611
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Qifan Chen commented on TRAFODION-1669:
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Reduce the CQD value to 500 as a comprise. Regression tests will issue lots of
failures when the default value is set to 100.
> Missing stats warnings threshold value (50,000) is too high
> -----------------------------------------------------------
>
> Key: TRAFODION-1669
> URL: https://issues.apache.org/jira/browse/TRAFODION-1669
> Project: Apache Trafodion
> Issue Type: Bug
> Components: sql-cmp
> Reporter: Qifan Chen
> Assignee: Qifan Chen
>
> Compiler currently does not give out warnings when the row count for a table
> is less than a threshold. This threshold is currently set at 50,000 (through
> CQD HIST_ROWCOUNT_REQUIRING_STATS).
> A threshold value of 50,000 can mask out the missing stats risks for the
> operational workloads, since the small tables are joined with other tables
> and the result of the join can probe a fact table in a nested join. To cost
> nested joins correctly, we want precise row count.
> I plan to make a change to this CQD for it to use the same value as
> HIST_NO_STATS_ROWCOUNT (currently at 100). Any tables with no rows or # of
> rows less than 100 will not be the subject of missing stats warnings. For
> tables with more # of rows, the compiler will provide warnings (if needed).
>
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