Search Results for: snapper

Oracle hidden costs revealed, Part2 – Using DTrace to find why writes in SYSTEM tablespace are slower than in others

I have written two posts in one, about a performance issue with writes in system tablespace and introduction of a little DTrace stack sampling script. Have you noticed that DML on tables residing in SYSTEM tablespace is slower than tables … Continue reading

Posted in Oracle | Tagged , , , , | 26 Comments

Advanced Oracle Troubleshooting Guide, Part 8: Even more detailed latch troubleshooting using LatchProfX

In my last AOT post I published my LatchProf script which is able to sample detailed latchholder data from V$LATCHHOLDER. Latchprof allows you to drill down into your latching problems at session level (which V$LATCH, V$LATCH_PARENT and V$LATCH_CHILDREN can’t do). … Continue reading

Posted in Cool stuff, Oracle | Tagged , , , | 9 Comments

Another use case for WaitProf – diagnosing “events in waitclass Other”

I recently diagnosed a performance issue where the “events in waitclass Other” occasionally took significant part of the session’s response time. For example Snapper (which reads wait event data from V$SESSION_EVENT) reported that during measuring 39.9% of the response time … Continue reading

Posted in Oracle | Tagged , , , | 7 Comments