exec DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS( INTERVAL=>0 );

select * from DBA_HIST_WR_CONTROL

DBID SNAP_INTERVAL RETENTION TOPNSQL
1898043910 +40150 00:00:00.000000 +07 00:00:00.000000 30

select * from DBA_HIST_WR_CONTROL
DBID SNAP_INTERVAL RETENTION TOPNSQL
1898043910 +00 01:00:00.000000 +01 00:00:00.000000 DEFAULT

exec DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(topnsql => 30);

select * from DBA_HIST_WR_CONTROL
DBID SNAP_INTERVAL RETENTION TOPNSQL
1898043910 +00 01:00:00.000000 +01 00:00:00.000000 30

===== How to change the Retention of AWR Snapshot in 10g

select * from DBA_HIST_WR_CONTROL
DBID SNAP_INTERVAL RETENTION TOPNSQL
1898043910 +00 01:00:00.000000 +07 00:00:00.000000 DEFAULT

Currently it is set to have retention of AWR snapshot for 7 days. Below command will change the snapshot to 10 days.

EXECUTE DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(retention => 60*24*10)

select * from DBA_HIST_WR_CONTROL

DBID SNAP_INTERVAL RETENTION TOPNSQL
1898043910 +00 01:00:00.000000 +10 00:00:00.000000 DEFAULT

select * from DBA_HIST_WR_CONTROL

DBID SNAP_INTERVAL RETENTION TOPNSQL
1898043910 +00 01:00:00.000000 +07 00:00:00.000000 DEFAULT

exec DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS( INTERVAL=>120 );

select * from DBA_HIST_WR_CONTROL

DBID SNAP_INTERVAL RETENTION TOPNSQL
1898043910 +00 02:00:00.000000 +07 00:00:00.000000 DEFAULT

Question:
set the audit_trail parameter in the database to “db”, it generates lot of records in sys.aud$ table. can you suggest any method to overcome this issue?. we need to activate audit_Trail parameter as part of oracle auditing requirements. earlier it was set to db but due to performance issues it has been set to false now. can you suggest ways to overcome this problem ours is oracle 9.2.0.6 version.

Suggestion:
1.When you set audit it does audit for every single activity on the database. So it may lead into performance problem.
You have to disable every single audit(<> noaudit) before or after you set the parameter and then enable one by one based on the requirement.
2. You should monitor the growth of sys.aud$ and archive it properly or maintain the space.