Performance Engineering Interview Questions #2

Following are the Performance Engineering Interview Questions Set #2.

Q. 6 What is an AWR?

Ans: The full form of AWR is Automatic Workload Repository. It is a built-in repository in the Oracle database that collects, processes and maintains performance statistics. AWR captures data on system load, wait events, SQL execution and more at regular intervals.

Q. 7 How does AWR help?

Ans: AWR helps a DBA or a Performance Engineer to analyse the DB performance, identify DB-related bottlenecks and provide leads to tune the Database. It collects and summarises system load, wait events, SQL execution and more over a specified period. A Performance Engineer refers to the specific section and finds out the problematic queries which degrade the performance of the database.

Q. 8 How to generate an AWR report?

Ans. AWR report is generated using awrrpt.sql script which is located in $ORACLE_HOME/rdbms/admin directory.

Run awrrpt.sql in SQL Plus
Choose Type of Report (e.g. html)
Enter no. of days (e.g. 1)
Enter the snapshot ID of the beginning period.
Enter the snapshot ID of the ending period.
Enter the name of the report

Refer to the article to get all the steps of AWR report generation…

Q. 9 What are the snapshots in AWR?

Ans: Snapshots contain the performance metrics data of an Oracle Database that is collected over the period. The snapshots are stored in the repository so that AWR reports can be generated at any time of a specific period.

Q. 10 What is the default period for taking snapshots in Oracle?

Ans: Every hour. This period can be changed. The default period to store the snapshot is 8 days.