Tools and Utilities - Expert Oracle RAC Performance Diagnostics and Tuning - page 152

Automatic Workload Repository Warehouse
The default retention period for an AWR in Oracle Database 11g is eight days, and seven days for the previous releases.
This minimal retention period is hardly sufficient for analyzing historical behavior or trend analysis related to specific
issues around the database. As a best practice, the retention period is increased so historical information can be
retained and analyzed if required; however, increasing the retention period for a considerably longer interval has some
negative impact on the primary database, such as increased space usage, contention with read write operations, etc.
A new feature introduced in Oracle 12c allows the creation of an Automatic Workload Repository
Warehouse (AWRW). Figure 6-9 illustrates the basic high-level process for creating the repository. AWR data is
collected from various target databases and stored in a central repository or warehouse. From the warehouse
additional reports can be generated.

Figure 6-9. AWR warehouse

The following are the steps to create an AWRW.

1.

Connect to the EM Cloud Control console with super administrator privileges.

2.

From the Targets menu, select Databases.

3.

On the Databases page, click the Performance tab, then select the AWR Warehouse option
from the pull-down menu.

4.

Click Configure. The first configuration page (Repository) appears.

5.

Click the search icon to select the database to serve as the AWR warehouse.

6.

Select the preferred or named credentials established for the target database and the target
database host, and click Next.