Running index statistics

Authorities and privileges

To run index statistics:

1. Open the Index Statistics window.
2. On the Options pages, specify how the utility runs.
3. On the Indexes pages, specify correlation statistics properties.
4. Click OK.

Specifying how the utility runs

1. Specify a Share level

Reference only

Allows read-only access to other applications while the utility is running.

Allow changes

Allows write access to other applications while the utility is running. This setting can allow uncommitted data to be collected in the statistical report.

2. Specify Yes or No in the Report statistics radio buttons. Specifying Yes indicates that a set of messages is sent to the SYSPRINT data set.
3. Specify how you want the utility to update the DB2 catalog:
Access path and space statistics
The utility updates all the statistics.
Access path statistics only
The utility updates only the catalog tables used for access path selection.
Space statistics only
The utility updates only the catalog that provide statistics to help database administrators assess the status of a space or index.

Specifying correlation statistics properties

1. Specify the Collect key cardinalities check box to collect all of the distinct values in all of the 1 to n key column combinations for the specified indexes, where  n is the number of columns in the index.
2.  To collection frequent value statistics, select the index in the table and click the Add push button.

The Index Correlation Statistics window opens.