What is the impact on database performance of turning on all the new database manageability features?
All the new manageability features with the exception of Automatic SGA Memory Tuning are enabled when the initialization parameter STATISTICS_LEVEL is set to TYPICAL, which is its default value. When the STATISTICS_LEVEL parameter is set to TYPICAL and Automatic SGA Memory Tuning is also enabled, the impact on performance is under 5%. In fact, of the various applications tested, the worst-case performance degradation observed was only about 3.4%, while most applications showed 1% or smaller performance impact. Keep in mind that performance overhead is relative to a perfectly tuned application. Given that most real-world applications are not perfectly tuned, they can actually expect to see a performance improvement in their applications since many of the new manageability features proactively enhance database performance without requiring any manual intervention by a DBA or a performance engineer.
