AWR & ASH: Oracle Performance Tools

AWR (Automatic Workload Repository) and ASH (Active Session History) are crucial tools in Oracle databases for performance tuning and troubleshooting.

AWR is a performance diagnostic tool in Oracle databases that automatically collects performance data of the database instance regularly, such as system activity, wait events, and SQL execution details. This data can assist DBAs in analyzing performance bottlenecks and optimizing database performance.

ASH is a special table in the Oracle database that records relevant information about active sessions in the database instance, such as session wait events, SQL execution status, and execution plans. By analyzing ASH data, one can understand which sessions are currently executing, which sessions are waiting for resources, and the overall performance of the system.

Utilizing both AWR and ASH together can assist DBAs in gaining a better understanding of a database instance’s performance status, enabling them to promptly identify and resolve performance issues, ultimately improving system stability and performance.