[
https://issues.apache.org/jira/browse/DERBY-4939?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13010703#comment-13010703
]
Dag H. Wanvik commented on DERBY-4939:
--------------------------------------
Small comment on the release notes:
> "During query compilation, Derby now checks if the index cardinality
> statistics for the tables involved in the query are out of date. If > the
> statistics are outdated, the query compiler will schedule a job that updates
> them in a separate thread. "
Strictly speaking, "out-of-date" is an elusive goal, we can't really claim more
than a best shot using heuristics. So maybe we should
qualify this statement to say something like "deemed out of date", and add a
sentence to say that one can always force an update using
SYSCS_UTIL.SYSCS_UPDATE_STATISTICS if the automation doesn't work well enough
for an application?
> Enable istat daemon and tests
> -----------------------------
>
> Key: DERBY-4939
> URL: https://issues.apache.org/jira/browse/DERBY-4939
> Project: Derby
> Issue Type: Sub-task
> Components: SQL
> Affects Versions: 10.8.0.0
> Reporter: Kristian Waagan
> Assignee: Kristian Waagan
> Fix For: 10.8.0.0
>
> Attachments: derby-4939-1a-enable_istat.diff, releaseNote.html,
> releaseNote.html, releaseNote.html, releaseNote.html
>
>
> Enable automatic updates and creations of index cardinality statistics, and
> wire the tests into the regression suite.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
