Automatic Workload Repository (AWR) in Oracle Database 10g

AWR Features

The AWR is used to collect performance statistics including:
A) Wait events used to identify performance problems.
B) Time model statistics indicating the amount of DB time associated with a process from the V$SESS_TIME_MODEL and V$SYS_TIME_MODEL views.
C) Active Session History (ASH) statistics from the V$ACTIVE_SESSION_HISTORY view.
D) Some system and session statistics from the V$SYSSTAT and V$SESSTAT views.
E) Object usage statistics.
F) Resource intensive SQL statements.

The repository is a source of information for several other Oracle 10g features including:
Automatic Database Diagnostic Monitor
SQL Tuning Advisor
Undo Advisor
Segment Advisor