optdiag can generate statistics that can be used to simulate a user environment without requiring a copy of the table data. This permits analysis of query optimization using a very small database. For example, you can use simulated statistics to:
Help Technical Support replicate optimizer problems
Perform “what-if” analyses to plan configuration changes
Perform diagnostics on a development server.
See “Requirements for loading and using simulated statistics”.
You can also load simulated statistics into the database from which they were copied. Simulated statistics are loaded into the system tables with IDs that distinguish them from actual table data. The set statistics simulate on command instructs the server to optimize queries using the simulated statistics, rather than the actual statistics.