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From "Kristian Waagan (JIRA)" <j...@apache.org>
Subject [jira] Updated: (DERBY-269) Provide some way to update index cardinality statistics (e.g. reimplement update statistics)
Date Tue, 10 Apr 2007 17:00:32 GMT

     [ https://issues.apache.org/jira/browse/DERBY-269?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Kristian Waagan updated DERBY-269:
----------------------------------

    Affects Version/s:     (was: 10.0.2.2)
                       10.3.0.0
                       10.2.2.0

Added 10.2.2.0 to the affected version list, as a user has reported severe performance degradation
due to this issue. See http://www.nabble.com/Performance-Tuning-Problem-tf3549175.html for
details. It is likely that trunk suffers from the same issue, so I'm adding that one as well.

> Provide some way to update index cardinality statistics (e.g. reimplement update statistics)
> --------------------------------------------------------------------------------------------
>
>                 Key: DERBY-269
>                 URL: https://issues.apache.org/jira/browse/DERBY-269
>             Project: Derby
>          Issue Type: New Feature
>          Components: SQL
>    Affects Versions: 10.0.2.0, 10.0.2.1, 10.1.1.0, 10.2.2.0, 10.3.0.0
>            Reporter: Stan Bradbury
>
> Performance problems are being reported that can be resolved by updating the cardinality
statistics used by the optimizer.  Currently the only time the statistics are guaranteed to
be an up-to-date is when the index is first created on a fully populated table.  This is most
easily accomplished on an existing table by using the command: 
>    alter table <table-name> compress [sequential]  
> Compress table is an I/O intensive task.  A better way to achieve this would be to re-enable
parser support for the 'update statistics' command or re-implement the update in some other
fashion.

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