[ 
https://issues.apache.org/jira/browse/DERBY-6283?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13706351#comment-13706351
 ] 

Kathey Marsden commented on DERBY-6283:
---------------------------------------

Thanks Mike, I verified the trunk fix with a 10.3 user database that had 
disposable stats.  The repro does repeated selects on the problematic table. 
Without the fix and soft upgrade, the rows did not get dropped and the index 
stat daemon repeatedly invoked. With the fix, the rows were deleted and after 
updating the stats the first time index stat daemon did not invoke again.
                
> indexStat daemon processing tables over and over even when there are no 
> changes in the tables in soft upgraded database.
> ------------------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-6283
>                 URL: https://issues.apache.org/jira/browse/DERBY-6283
>             Project: Derby
>          Issue Type: Bug
>          Components: Store
>    Affects Versions: 10.8.3.1, 10.9.2.2, 10.10.1.3, 10.11.0.0
>            Reporter: Mike Matrigali
>            Assignee: Mike Matrigali
>            Priority: Blocker
>              Labels: derby_triage10_11
>         Attachments: derby-6283.diff
>
>
> The fix for DERBY-5680 currently requires hard upgrade.  A soft upgrade 
> database with an orphaned stat row, that can be caused by something like 
> DERBY-5681, will cause DERBY to spin eating up 100% of a cpu and possibly all 
> the disk bandwith of the disk where the database is located.
> We should implement a fix that can be applied to soft upgraded databases if 
> at all possible.
> In soft upgraded databases we can no use the work around of dropping the 
> statistics as it is not available
> to soft upgraded db's with version < 10.9.  The only current workaround is to 
> disable background stats
> completely.  Dropping and recreating the suspect table may also work.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to