Unlike the other advisors, the ADDM runs automatically after each AWR snapshot. Each time a snapshot is taken, the ADDM performs an analysis of the period corresponding to the last two snapshots. The ADDM proactively monitors the instance and detects most bottlenecks before they become a significant problem.
In many cases, the ADDM recommends solutions for detected problems and
even quantifies the benefits for the recommendations.
Some common problems that are detected by the ADDM:
•
CPU bottlenecks
•
Poor Oracle Net connection management
•
Lock contention
•
Input/output (I/O) capacity
• Undersizing of database instance memory
structures
•
High-load SQL statements
•
High PL/SQL and Java time
• High checkpoint load and cause (for
example, small log files)
The results of each ADDM analysis are stored in the AWR and are also
accessible through Enterprise Manager.
