Differences between AWR and STATSPACK report

1)Statspack snapshot purges must be scheduled manually. When the Statspack tablespace runs out of space, Statspack quits working. AWR snapshots are purged automatically by MMON every night. MMON, by default, tries to keep one week's worth of AWR snapshots available. If AWR detects that the SYSAUX tablespace is in danger of running out of space, it will free space in SYSAUX by automatically deleting the oldest set of snapshots. If this occurs, AWR will initiate a server-generated alert to notify administrators of the out-of-space error condition. 

2)The AWR repository holds all of the statistics available in STATSPACK as well as some additional statistics which are not.

3)STATSPACK does not store the Active Session History (ASH) statistics which are available in the AWR dba_hist_active_sess_history view.

4)STATSPACK does not store history for new metric statistics introduced in Oracle. The key AWR views are: dba_hist_sysmetric_history and dba_hist_sysmetric_summary.

5)The AWR also contains views such as dba_hist_service_stat , dba_hist_service_wait_class and dba_hist_service_name , which store history for performance cumulative statistics tracked for specific services.

6)The latest version of STATSPACK included with Oracle contains a set of specific tables, which track history of statistics that reflect the performance of the Oracle Streams feature. These tables are stats$streams_capture , stats$streams_apply_sum , stats$buffered_subscribers , stats$rule_set , stats$propagation_sender , stats$propagation_receiver and stats$buffered_queues . The AWR does not contain the specific tables that reflect Oracle Streams activity; therefore, if a DBA relies heavily on the Oracle Streams feature, it would be useful to monitor its performance using STATSPACK utility.

7)Statspack snapshots must be run by an external scheduler (dbms_jobs, CRON, etc.). AWR snapshots are scheduled every 60 minutes by default.

8)ADDM captures a much greater depth and breadth of statistics than Statspack does. During snapshot processing, MMON transfers an in-memory version of the statistics to the permanent statistics tables.