[ http://issues.apache.org/jira/browse/DERBY-269?page=all ]
Mike Matrigali updated DERBY-269:
---------------------------------
Component: SQL
Description:
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.
was:
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.
Environment:
> 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
> Components: SQL
> Versions: 10.0.2.0, 10.0.2.1, 10.1.1.0, 10.0.2.2
> 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.
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
http://www.atlassian.com/software/jira
