[jira] [Resolved] (TRAFODION-1669) Missing stats warnings threshold value (50,000) is too high

["Qifan Chen (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/TRAFODION-1669?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Qifan Chen resolved TRAFODION-1669.
-----------------------------------
    Resolution: Fixed

> 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). 
>  



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)