A variation on Tom Kyte's invaluable RUNSTATS utility that compares the resource consumption of two alternative units of work. Designed to work under constrained developer environments and builds on the original with enhancements such as "pause and resume" functionality, time model statistics and the option to report on specific statistics. ***Update*** Now available in two formats: 1) as a PL/SQL package and 2) as a free-standing SQL*Plus script (i.e. no installation/database objects needed). January 2007 (updated October 2011)
A variation on Jonathan Lewis's SNAP_MY_STATS package to report the resource consumption of a unit of work between two snapshots. Designed to work under constrained developer environments, this version has enhancements such as time model statistics and the option to report on specific statistics. ***Update*** Now available in two formats: 1) as a PL/SQL package and 2) as a free-standing SQL*Plus script (i.e. no installation/database objects needed). June 2007 (updated October 2011)
Monday: I went to some presentations, hung around in the OTN lounge and ate at every possible opportunity. Tanel Poder‘s presentation on “Large-Scale Consolidation onto Oracle Exadata: Planning, Execution, and Validation” was pretty cool.
In the evening I planned to meet a former colleague at the OTN party. I decided they best way to find him was to visit every food station at the party, which of course meant sampling the goods. Unfortunately I spent too much time eating and not enough time looking for him. Sorry Ian! The cool thing about Open World is you can enter a giant tent full of thousands of people and pretty much guarantee you will bump into loads of people you know.
Tuesday: I spent most of Tuesday helping out at RAC Attack in the OTN Lounge. I did manage to get to see Greg Rahn‘s presentation called “Real-World Performance: How Oracle Does It”, which focussed on Real-Time SQL Monitoring. Greg’s presentation style is really easy to listen to and you know this isn’t just theoretical knowledge. He’s in the trenches doing this stuff as part of the Real-World Performance Group.
As the afternoon progressed I felt a little tired, so I went back to the hotel, puked and fell asleep. I think this was more to do with being over-tired than anything else. That meant I missed some of the later sessions and didn’t hook up with anyone in the evening.
This morning I feel a little ropey, but I’m going to head on down to RAC Attack again and see if I can make myself useful. Tonight is the appreciation event, but I’m not sure if I will be able to “appreciate it” unless I get a major energy injection at some point today.
There seems to be a little confusion out there about the certification status of Oracle Database 11gR2, especially with the release of the 188.8.131.52 patchset which fixes all the issues associated with RAC installs on OL/RHEL 6.1.
Currently, 11gR2 is *NOT* certified on OL6 or RHEL6. How do I know? My Oracle Support says so! Check for yourself like this:
From the results you will see that Oracle Database 184.108.40.206 is certified on OL and RHEL 5.x. Oracle do not differentiate between different respins of the major version. You will also notice that it is not currently supported on OL6 or RHEL6.
Having said that, we can expect this certification really soon. Why? Because Red Hat has submitted all the certification information to Oracle and (based on previous certifications) expects it to happen some time in Q4 this year, which is any time between now and the end of the year.
With a bit of luck, by the time I submit this post MOS certification will get updated and I will happily be out of date…
Today (Tuesday, October 4th 2011) I had my presentation at OOW 2011 in Hotel InterContinental at 13:15 titled "Getting the Best from the Cost Based Optimizer". The room was already sold out on Thursday and I really expected to have a full room - cca 270 people. The room was too small for all who want attending the presentation. Although there were no seats available quite a lot of them were standing in the back.
This time my presentation was not very technical one (in my eyes). I just wanted to point out problems I see many times in real life when people don't really know about some features or behavior of the CBO. Unfortunately one hour was not enough to explain in details why things are going wrong and also show all relevant details. But as I said, the aim was to point out the problems and also give directions what one has to do to get rid of them and according to the reactions of the audience after the presentation the goal was achieved.
SQL> create table test tablespace users as select rownum id, 'xxxxxxxxxxxxxxxxxxxxxxxx' col1 from dba_source, dba_source where rownum < 10000000; Table created.
October 4, 2011 An interesting, but poorly worded, problem appeared in an OTN thread recently where the OP claimed that a 10200 trace was not showing a consistent get, even though a concurrent 10046 trace’s EXEC and STAT lines indicated one consistent get. The provided test case and sample 10200/10046 trace left a couple of [...]
Hybrid Columnar Compression is one of the big features of Exadata that can make fairly dramatic differences to the amount of space it takes to store your data. But how do you find out what’s going on under the covers if you haven’t got an Exadata machine in your garage ?
Here’s a simple starting point that occurred to me a couple of days ago after the product manager (or some such) pointed out that there was no need to make an Exadata emulator available to anyone because all you needed was the compression advisor which you could trust because it actually compressed a sample of your data to see how well it could compress.