Automatic Database Diagnostic Monitor (ADDM)

Automatic Database Diagnostic Monitor (ADDM) and Automatic Workload Repository (AWR)

Automatic Database Diagnostic Monitor (ADDM)
http://docs.oracle.com/cd/B28359_01/server.111/b28275/tdppt_auto.htm

• Aautomatically detects and reports performance problems with the database

• The results are displayed as ADDM findings on the Database Home page in Oracle Enterprise Manager (Enterprise Manager)
• Reviewing the ADDM findings enables you to quickly identify the performance problems that require your attention.
• Each ADDM finding provides a list of recommendations for reducing the impact of the performance problem
• Reviewing ADDM findings and implementing the recommendations are tasks that you should perform daily as part of the regular database maintenance
• Even when the database is operating at an optimal performance level, you should continue to use ADDM to monitor database performance on an ongoing basis 

• ADDM examines and analyzes data captured in the Automatic Workload Repository (AWR) to determine possible performance problems in Oracle Database
• ADDM then locates the root causes of the performance problems, provides recommendations for correcting them, and quantifies the expected benefits. ADDM also identifies areas where no action is necessary
• The ADDM analysis is performed from the top down, first identifying symptoms and then refining the analysis to reach the root causes of performance problems. ADDM uses the DB time statistic to identify performance problems
• DB time is the cumulative time spent by the database in processing user requests, including both the wait time and CPU time of all user sessions that are not idle.