Customizing Update Statistics with SAPDBA (SAP Library - SAP Database Guide: Informix (BC-DB-INF-DBA))

Customizing Update Statistics with SAPDBA

Use

You can use this procedure to customize update statistics with SAPDBA for Informix, because the default values are often not suitable for large tables.

Prerequisites

You want to improve database performance on problematic large tables by making sure that update statistics is more accurate.

Procedure

Do one or both of the following to improve database performance:

Set up entries in the control table, DBSTATC , for specified tables. These entries override the default values used by SAPDBA whenever update statistics is run. See below for more details.

As well as setting up entries for large tables where a more accurate set of statistics is required, you can also exclude tables for which no update statistics is necessary (for example, static tables).

Run update statistics from the command line for selected large tables. See the parameter table in Updating Statistics from the Command Line with SAPDBA.

Note

The table DBSTATC overrides all threshold settings and levels, whether you are performing update statistics with SAPDBA using the normal menus or using the command line. For more information, see Log Table for Update Statistics with SAPDBA.

Result

For information about how to alter the control table DBSTATC , see Configuring Update Statistics in CCMS (Informix).

See also:

Informix documentation