Automatic Workload Repository: Overview

AWR is the infrastructure that provides services to Oracle Database 11g components to collect, maintain, and utilize statistics for problem detection and self-tuning purposes.

  The AWR infrastructure consists of two major parts:

An in-memory statistics collection facility that is used by various components to collect statistics. These statistics are stored in memory for performance reasons. Statistics stored in memory are accessible through dynamic performance (V$) views.

• AWR snapshots represent the persistent portion of the facility. The AWR snapshots are accessible through data dictionary (DBA) views and Database Control.

• The memory version of the statistics is transferred to disk on a regular basis by a background process called MMON (Manageability Monitor).

Important Links:

• ADDM and Database Time
• ADDM Performance Monitoring
• AWR Reports
• OS Statistics from AWR Reports