Loading simulated statistics adds rows that describe cache configuration to the sysstatistics table in the master database. To remove these statistics, use delete shared statistics. The command has no effect on the statistics in the database where the simulated statistics were loaded.
If you have loaded simulated statistics into a database that contains real table and index statistics, you can drop simulated statistics by either:
Using delete statistics on the table, which deletes all statistics, and running update statistics to re-create only the nonsimulated statistics, or,
Using optdiag (without simulate mode) to copy statistics out; then running delete statistics on the table, and using optdiag (without simulate mode) to copy statistics in.