Search Results for: snapper

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

Advanced Oracle Troubleshooting Guide, Part 5: Sampling V$ stuff with WaitProf. Really fast. Using SQL!

I bet you thought I’ll be writing about direct SGA access?! ;) Nope! Direct SGA access has excellent troubleshooting potential (as long as you know the shared memory data structures), but it has one major drawback – very few companies … Continue reading

Posted in Cool stuff, Oracle | Tagged , , , , | 27 Comments

Oracle hidden costs revealed, part 1 – Does a batch job run faster when executed locally?

This series is about revealing some Oracle’s internal execution costs and inefficiencies. I will analyze few situations and special cases where you can experience a performance hit where you normally wouldn’t expect to. The first topic is about a question … Continue reading

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