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From "Kathey Marsden (JIRA)" <derby-...@db.apache.org>
Subject [jira] Commented: (DERBY-269) Provide some way to update index cardinality statistics (e.g. reimplement update statistics)
Date Sun, 22 May 2005 14:00:53 GMT
     [ http://issues.apache.org/jira/browse/DERBY-269?page=comments#action_65955 ]
     
Kathey Marsden commented on DERBY-269:
--------------------------------------

Some sort of zero admin solution for updating statistics would be prefferable to the manual
'update statistics'

> Provide some way to update index cardinality statistics (e.g. reimplement update statistics)
> --------------------------------------------------------------------------------------------
>
>          Key: DERBY-269
>          URL: http://issues.apache.org/jira/browse/DERBY-269
>      Project: Derby
>         Type: New Feature
>     Versions: 10.0.2.0, 10.0.2.1, 10.0.2.2, 10.1.0.0
>     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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