Automatic Workload Repository (AWR)

Automatic Workload Repository (AWR)

 http://www.oracle-base.com/articles/10g/automatic-workload-repository-10g.php

http://docs.oracle.com/cd/E11882_01/server.112/e16638/autostat.htm



AWR is a separately licensed feature of the Oracle 11gR2 Diagnostic Pack

While Statspack reports will certainly provide sufficient details for I/O performance tuning, AWR reports offer significantly more detail, are easier to navigate, and are more efficient to execute because they access performance metric data that’s already been captured within AWR snapshots … and those snapshots were gathered in real time using direct memory access.)


http://docs.oracle.com/cd/E11882_01/server.112/e16638/autostat.htm#i27008

The Automatic Workload Repository (AWR) collects, processes, and maintains performance statistics for problem detection and self-tuning purposes. This data is both in memory and stored in the database. The gathered data can be displayed in both reports and views.
The statistics collected and processed by AWR include:

• Object statistics that determine both access and usage statistics of database segments
  
• Time model statistics based on time usage for activities, displayed in the V$SYS_TIME_MODEL and V$SESS_TIME_MODEL views
  
• Some of the system and session statistics collected in the V$SYSSTAT and V$SESSTAT views
  
• SQL statements that are producing the highest load on the system, based on criteria such as elapsed time and CPU time
  
• ASH statistics, representing the history of recent sessions activity