You find today's performance of your production database to be the best ever. Therefore, you want to be notified in the future whenever the performance degrades by 10% of today's performance.
What is the first step that you would take to ensure this?
A. create baseline metrics for today's performance
B. write the current database metrics to a database table and create a trigger to compare with future database statistics
C. write the current database metrics to a flat file and create an operating script to compare with future database statistics
D. write the current database metrics to a database table and create a procedure to compare with future database statistics
E. write the current database metrics to a database table and submit a job using DBMS_JOB to compare with future database statistic
Answer: A
Baselines
A baseline contains performance data from a specific time period that is preserved for comparison with other similar workload periods when performance problems occur. The snapshots contained in a baseline are excluded from the automatic AWR purging process and are retained indefinitely.