Automatic Workload Repository (AWR)
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.
From Performance Hub, you can generate and download a report of the gathered data.
AWR Report
An AWR report shows data captured between two points in time (or snapshots). Not only can you view diagnostic data of your database but you can also get instance level reports for Oracle Real Application Clusters (RAC) databases to view details about a specific instance.
AWR reports are divided into multiple sections. The content of the report contains the workload profile of the system for the selected range of snapshots. The HTML report includes links that you can use to navigate quickly between sections.
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$SYS_TIME_MODELandV$SESS_TIME_MODELviews -
Some of the system and session statistics collected in the
V$SYSSTATandV$SESSTATviews -
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