I didn’t get to update the blog yesterday because I had a little bit of an issue with my hosting provider. The site seems OK now, so sorry for any inconvenience it caused… 🙁
As mentioned previously, I didn’t get to see too many presentations in the first two days because of the “Ask the Experts” panel and “Meet and Greet” presentations, so I was determined to do as much as possible on Wednesday, so here’s what I went to see…
“Recent Enhancements in Oracle’s Cost Basede Optimizer” by Jonathan Lewis – Over the years I’ve read quite a bit of Jonathan’s stuff and it has become obvious to me that my brain is too small and squishy to think on that level for too long. Sometimes I read his stuff and think, “I rubbish and I’m going to give up!” With that in mind, I was a little nervous about this presentation, thinking it may confound me to the point of making me quit Oracle. Fortunately, he dummed it down to mortal-level and an went away thinking, “Cool! I know what I’m doing.” Nice one Jonathan! 🙂
“Oracle Real Application Clusters: Scale Up or Scale Out” by Erik Peterson & Lan Shao – I’ve been using RAC for quite some time and I’ve seen my share of issues, so I was interested to see some comparisons between single large nodes and many small nodes. The presentation was very “big picture”, so it didn’t contain much raw data, but it seems that scale out (lots of small nodes) gives much better performance than scale up (one node). By the presenters own admission, some of the performance comparisons were very surprising. If you are thinking about RAC, it might be worth taking a look at this overview to get a feel for the configurations you might want to consider. You have to remember, these performance benchmarks were specific for the China Lottery, high numbers of small OLTP transactions, so you can’t assume hybrid or warehouse systems will respond the same way. Interesting stuff though!
“Recent Advances in Automatic SQL” by Jonathan Lewis – Once again, I didn’t walk away feeling like a rank amateur, so thanks Jonathan! This was a quick run through a number of the automatic SQL tuning features in 9i and 10g. It’s well worth checking out this paper if you are new to the automatic SQL tuning features because it will help you avoid a number of common mistakes people make when using these features.
“Tuning Oracle9i and Oracle Database 10g with Statspack and Oracle AWR Report” by Rich Niemiec – This presentation contained about 130 slides, most of which had numerous subsections. As a result, it felt like 500 slides in 60 minutes and I’m sure this confused this hell out of the newbies in the crowd. That said, Rich is a funny and interesting presenter. A little time was spent discussing the use of hit ratios for tuning, which you don’t hear a lot of these days. His attitude was, variations in hit ratios can give an indication that something has changed in the system, not that specific values of the ratios mean good or bad performance.
I also spent a lot of time at the trade stands speaking to techies, rather than sales staff. You can get some very useful real-world information from some of these people, and it’s not all biased in favour of their products.
It was a really busy and ejoyable day, but by the time I got back to the hotel I was too tired to go out again, so I just went to bed. 🙂