You can use the SQL Performance Analyzer to analyze the SQL performance impact of any type of system change. Examples of common system changes include: *Database upgrades *Configuration changes to the operating system, hardware, or database *Database initialization parameter changes *Schema changes, such as adding new indexes or materialized views *Gathering optimizer statistics *SQL tuning actions, such as creating SQL profiles http://docs.oracle.com/cd/B28359_01/server.111/b28318/intro.htm#CNCPT961