Note: This blog post actually serves three purposes:
Lately I’ve been using SQL runtime execution statistics combined with SQL monitor for performance diagnostics and, honestly, almost forgot about SQL trace. So this note is not very useful to me but it might be to someone: along with ALL_EXECUTIONS option appeared in (I believe) 11gR2, there’s a new option starting with 184.108.40.206 which can significantly decrease amount of data in the trace files for STAT lines compared to ALL_EXECUTIONS, still providing some of them from time to time.
Here is a case to demonstrate:
July 31, 2012 I encountered an interesting OTN thread that caused me to stop and think for a couple of minutes. The OP (original poster) in the OTN thread wondered why parallel execution was used for a query when the parallel degree for the table accessed by the query and its indexes were specified to have [...]
There’s no such thing as proactive tuning. Either you do it right before it goes into production (in which case it’s called “design”) or you react to the nasty surprises you get after it’s gone live.
Even if you do something about the problems before anyone has complained that’s still “reactive” not “proactive” – and the trick is to be reactive as soon as possible. For most companies the best strategy is probably to stick a big screen on the wall with the “Top Activity” page from OEM (or equivalent) so that the key players (DBAs and Developers) can keep a casual eye out for resource hogs and prioritise dealing with them as they appear.
July 8, 2012 As I was reading a book, I saw a comment essentially stating that with multiple CPUs/cores, parallel execution will be faster than serial execution of the same query. The book provided a test case - I decided to change around the test case a bit so that the results were a bit more fair, [...]
I’ll be co-speaking with Randy Johnson (one of the authors of Expert Oracle Exadata) at E4 to share about the war stories and detail on a bunch of technical stuff on a Peoplesoft and BIEE consolidation project we had on one of our clients. See the abstract below:
Last week I had a lengthy post at oracle-l that tackles Calibrate IO, Short Stroking, Stripe size, UEK kernel, and ASM redundancy effect on IOPS Exadata which you can read here
followed by interesting exchange of tweets with Kevin Closson here (see 06/21-22 tweets) which I was replying in between games at UnderwaterHockey US Nationals 2012 which we won the championship for the B division I have my awesome photo with the medal here
June 28, 2012 (Modified June 28, 2012) Sometimes it is possible to build a very effective test case to reproduce a particular problem. Sometimes the test case drifts a bit offtrack, in the process revealing other information that is not directly related to the original problem that the test case attempted to simulate. You will [...]
A short update on the how, what and where. I got really annoyed with the website performance, so hereby a different look and feel that hopefully (trimmed and all) will provide a faster load time of pages and other material. I also introduced some caching mechanisms that hopefully will be helpful. A faster reference to