While using buffer cache advisory, you find that no statistics have been collected. Which task would you perform to collect the statistics?
Restart the database instance.
Set DB_CACHE_ADVICE to ON.
Set TIMED_STATISTICS to TRUE.
Set TIMED_OS_STATISTICS to 100.
Set ACTIVE_INSTANCE_COUNT to 2.
Set STATISTICS_LEVEL to TYPICAL.
Modify the AUTO_TASK_JOB_CLASS schedule class.
Wait for the default automatic optimizer statistics generation.
Create a custom Automatic Database Diagnostic Monitor (ADDM) task.
If no statistics have been collected, them the automatic statistics colletion isn’t enable. The Oracle gathering and monitoring features are mainly automatic, managed by an Oracle background processes. To enable automatic statistics collection and automatic performance features, the STATISTICS_LEVEL initialization parameter must be set to
TYPICAL or ALL.
REF.: Oracle(r) 10g Performance Guide , 1-4