Following are the Performance Engineering Interview Questions Set #20. Q. 96 How can you correlate database CPU usage with SQL execution in the AWR report? Ans: Examine the “SQL Ordered by CPU Time” section to identify SQL statements consuming the most CPU. Cross-reference with overall CPU usage statistics to assess their impact on database performance. … Read more
Following are the Performance Engineering Interview Questions Set #19. Q. 91 How does the “Top Timed Events” section help in identifying bottlenecks? Ans: It lists the wait events that consumed the most time during the snapshot period, allowing you to focus on the most significant performance inhibitors. Q. 92 What is the significance of the … Read more
Following are the Performance Engineering Interview Questions Set #16. Q. 76 Explain the “latch: cache buffers chains” wait event and its impact. Ans: This wait event indicates contention for cache buffer chain latches, which protect the hash chains of buffer headers in the buffer cache. High waits suggest hot blocks or heavy concurrent access to … Read more
Following are the Performance Engineering Interview Questions Set #15. Q. 71 How can you reduce the ‘Buffer Busy Waits’ identified in the AWR report? Ans: It can be reduced by: Q. 72 What are wait events in Oracle, and why are they important for performance analysis? Ans: Wait events represent the time sessions wait for … Read more
Following are the Performance Engineering Interview Questions Set #14. Q. 66 What is the difference between ‘db file sequential read’ and ‘db file scattered read’ wait events? Ans: The ‘db file sequential read’ indicates single-block reads, often associated with index lookups whereas ‘db file scattered read’ involves multi-block reads, typically from full table scans or … Read more
In AWR, the ‘Instance CPU’ table comes under the ‘Report Summary’ section. Refer to the below figure: To analyse the ‘Instance CPU’ section, you must Look at the Host CPU and Instance CPU sections. The key things to look for are the values “%Idle” in the “Host CPU” section and “%Total CPU” in the “Instance … Read more