When the statistics are loaded into the original database, they are placed in separate rows in the system tables, and do not overwrite existing non-simulated statistics. The simulated statistics are only used for sessions where the set statistics simulate command is in effect.
While simulated statistics are not used to optimize queries for other sessions, executing any queries by using simulated statistics may result in query plans that are not optimal for the actual tables and indexes, and executing these queries may adversely affect other queries on the system.
