
You can update statistics on the Oracle database using the Computing Center Management System (CCMS).
By running update statistics regularly, you make sure that the database statistics are up-to-date, so improving database performance. The Oracle cost-based optimizer (CBO) uses the statistics to optimize access paths when retrieving data for queries. If the statistics are out-of-date, the CBO might generate inappropriate access paths (such as using the wrong index), resulting in poor performance.
The CBO is a standard part of the SAP system. If statistics are available for a table, the database system uses the cost-based optimizer. Otherwise, it uses the rule-based optimizer.
You can also run update statistics for your Oracle database using BRCONNECT. Refer to Update Statistics with BRCONNECT. This is the recommended way to update statistics.
Update statistics after installations and upgrades
You need to update statistics for all tables in the SAP system after an installation or an upgrade. This is described in the relevant installation or upgrade documentation.
You use the DBA Planning Calendar in CCMS to schedule regular execution of check statistics and, if necessary, update statistics. For more information, see Updating Statistics in the DBA Planning Calendar (Oracle).
If required, you run one-off checks on tables to see if the table's statistics are out-of-date, and then run an update statistics for the table if required. This is useful, for example, if the data in a table has been significantly updated, but the next scheduled run of update statistics is not for a long time.
You can check, create, update, or delete statistics for:
If required, you configure update statistics by amending the parameters in the control table DBSTATC . This control table contains a list of the database tables for which the default values for update statistics are not suitable. If you change this table, all runs of update statistics - in BRCONNECT, CCMS, or the DBA Planning Calendar - are affected.
Configuring update statistics makes sense with large tables, for which the default parameters might not be appropriate.
Do not add, delete, or change table entries unless you are aware of the consequences.