How to Use the SYSSTAT Tables to Perform What-if Modeling and Analysis
Because DB2 maintains the SYSIBM and SYSCAT system catalog tables and views, they are read-only. However, you can update the SYSSTAT views. This is a special set of views that you can use to update database statistics. The information contained in these views affects how the DB2 optimizer chooses access plans when executing a query.
For planning purposes, you can change the statistical information in the SYSSTAT tables so that they do not reflect the actual state of tables and indexes. This lets you:
Model query performance on a development system using production system statistics.
Perform what-if query performance analysis by examining various possible changes to the query ...
Get Understanding DB2®: Learning Visually with Examples now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
