Oracle AWR Report Analysis.

AWR:- Automatic Workload Repository.

AWR Report collects operation statistics and also other statis about a specific database. Oracle takes a snapshot of all its important statistics and load information at fixed intervals (the default is 1 hour) and stores the snapshot in AWR. This information is retained in AWR for a specified period of time (the default is 1 week) and then deleted.
The frequency and duration of snapshot execution can be customized.