4 Optimize query engine performance

To optimize the performance of the query engine, refresh statistics by running stored procedure REFRESH_STATS_TAB.

Execute this procedure:

• After the initial CDM data load.
• After any significant changes in data volumes or distribution in the CDM schema.
• Periodically.

To execute the procedure:

1. On the database server, log in to SQL*Plus as CDM.
2. Execute the following commands:

   set serveroutput on
   set echo on
   spool REFRESH_STATS_TAB
   execute REFRESH_STATS_TAB
   spool off
   exit