How to invoke, collect and run AWR and statspack report

By default, AWR automatically generates snapshots of the performance data once every hour and retains the statistics in the workload repository for 7 days.

The data in the snapshot interval is then analyzed by the Automatic Database Diagnostic Monitor (ADDM).

However if you want to create, drop or modify snapshot manually then you can use DBMS_WORKLOAD_REPOSITORY procedures. To invoke these procedures, a user must be granted the DBA role.

To see the result by using AWR just create snapshot by DBMS_WORKLOAD_REPOSITORY.CREATE_SNAPSHOT and then execute your transaction or SQL statements and again create another snapshot by DBMS_WORKLOAD_REPOSITORY.CREATE_SNAPSHOT and then follow Generating Automatic Workload Repository Reports section to see report between these two snapshots.

Creating Snapshot
BEGIN
DBMS_WORKLOAD_REPOSITORY.CREATE_SNAPSHOT ();
END;
/

To view a list of the snapshot Ids along with database Ids, check the DBA_HIST_SNAPSHOT view.

Dropping Range of Snapshots.
Check the DBA_HIST_SNAPSHOT view column SNAP_ID to view available snapshots. To delete contain SNAP_ID from from 32 to 42,
BEGIN
DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE (low_snap_id => 32,
high_snap_id => 42, dbid => 8999917127);
END;
/


Modifying Snapshot Settings
If you want to modify the retention period as 43200 minutes (30 days), the interval between each snapshot is specified as 30 minutes, and the number of Top SQL to flush for each SQL criteria as 100 then issue,
BEGIN
DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS( retention => 43200,
interval => 30, topnsql => 100, dbid => 3310949047);
END;
/
Here dbid is optional.

Extracting AWR Data
The awrextr.sql script extracts the AWR data for a range of snapshots from the database into a Data Pump export file. Once created, this dump file can be transported to another system where the extracted data can be loaded. To run the awrextr.sql script, you need to be connected to the database as the SYS user.

To extract AWR data at the SQL prompt, enter:

@$ORACLE_HOME/rdbms/admin/awrextr.sql

Loading AWR Data

Once the export dump file is transported to the target system, you can load the extracted AWR data using the awrload.sql script. The awrload.sql script will first create a staging schema where the snapshot data is transferred from the Data Pump file into the database. The data is then transferred from the staging schema into the appropriate AWR tables. To run the awrload.sql script, you need to be connected to the database as the SYS user.

To load AWR data at the SQL prompt, enter:

@$ORACLE_HOME/rdbms/admin/awrload.sql

Generating Automatic Workload Repository Reports

If you have EM available then from EM you can easily generate AWR report. To generate on home page click Advisor Central and follow the links. However you can generate AWR reports by running SQL scripts:

The awrrpt.sql SQL script generates an HTML or text report that displays statistics for a range of snapshot Ids.
To generate an HTML or text report for a range of snapshot Ids, run the awrrpt.sql script at the SQL prompt:

@$ORACLE_HOME/rdbms/admin/awrrpt.sql

First, you need to specify whether you want an HTML or a text report.

Enter value for report_type: text

Specify the number of days for which you want to list snapshot Ids.

Enter value for num_days: 2

After the list displays, you are prompted for the beginning and ending snapshot Id for the workload repository report.

Enter value for begin_snap: 90
Enter value for end_snap: 92

Next, accept the default report name or enter a report name. The default name is accepted in the following example:

Enter value for report_name:
Using the report name awrrpt_1_90_92

The workload repository report is generated.

The awrrpt.sql SQL script generates an HTML or text report that displays statistics for a range of snapshot Ids.


The awrrpti.sql SQL script generates an HTML or text report that displays statistics for a range of snapshot Ids on a specified database and instance.


The awrsqrpt.sql SQL script generates an HTML or text report that displays statistics of a particular SQL statement for a range of snapshot Ids. Run this report to inspect or debug the performance of a SQL statement.

The awrsqrpi.sql SQL script generates an HTML or text report that displays statistics of a particular SQL statement for a range of snapshot Ids on a specified database and instance. Run this report to inspect or debug the performance of a SQL statement on a specific database and instance.

The awrddrpt.sql SQL script generates an HTML or text report that compares detailed performance attributes and configuration settings between two selected time periods.


The awrddrpi.sql SQL script generates an HTML or text report that compares detailed performance attributes and configuration settings between two selected time periods on a specific database and instance.