October 2011

Organizing  some of my past blog entries on Oracle database performance tuning and analysis. I’ll add more notes as well as a separate section on SQL tuning in particular.

ASH

• SQL execution times from ASH – using ASH to see SQL execution times and execution time variations
• AAS on AWR – my favorite ASH query that shows AAS  wait classes  as an ascii graph
• CPU Wait vs CPU Usage – seeing OS CPU usage, Oracle CPU usage and Oracle wait for CPU using ASH
• Simulated ASH 2.1 – get your ASH for free

AWR

My flights to China were rather uneventful. The Birmingham to Dubai leg was delayed by an hour due to fog in Dubai. I had a 4 hour connection in Dubai originally, so the delay was no big deal.

Arriving in Beijing was a little unnerving. I misplaced the Chinese version of the hotel address, but had the English version. Finding someone to translate it proved very difficult and as it turned out they translated it incorrectly. Fortunately I found a cached version of the address on my iPad, so that saved by bacon. The second hitch was that I couldn’t get cash with by debit cards. Just a flat-out refusal from any ATM in China. Arrrggghhh! Fortunately, I was able to get cash advances using my credit card. I’m going to pay through the nose for it, but at least I can survive.

Today is the first day of the conference and I had a morning slot. For the English speakers, we had one screen showing our slides in English and one showing the Chinese translation. I was asked to speak more slowly than usual (kinda difficult for me) and as a result I had to reduce the content somewhat. I did a run through last night to make sure my timing was OK with this adjustment.

The conference has a single track, so you get a room full of people from different technical areas. This is always a little unnerving as you worry about the relevance of your material to audience. Here are a couple of photos of the audience I took while I was setting up.

Everything seemed to go OK. I hope they understood my accent.

With a bit of luck I will get to see some of Beijing over the next couple of days. I’m behing the Great Firewall of China, so some sites (Facebook and Twitter) are blocked completely and many other sites (like Gmail and any other Google related services) seem to come and go. For the time being my blog seems active. If I lose access to it I will update things once I get to New Zealand.

Cheers

Tim…

Book: 

Oracle Core: Essential Internals for Troubleshooting

 Oracle Core: Essential Internals for Troubleshooting by Jonathan Lewis provides just the essential information about Oracle Database internals that every database administrator needs for troubleshooting—no more, no less.
 
Oracle Database seems complex on the surface. However, its extensive feature set is really built upon upon a core infrastructure resulting from sound architectural decisions made very early on that have stood the test of time. This core infrastructure manages transactions and the ability to commit and roll back changes, protects the integrity of the database, enables backup and recovery, and allows for scalability to thousands of users all accessing the same data.

I’ve always been fascinated by development databases — more so sometimes than huge, heavily utilized production ones. Mainly because I’ve seen how the beginnings of a performance problem, or the start of an elegant solution takes shape within a development database. It’s one of the reasons why I love high levels of visibility through full DDL-auditing within development. I love to SEE what database developers are thinking, and how they are implementing their ideas using specific shapes of data structures.

One of the concepts I’d love to see is a “river of news” panel within development tools to see what is going on within a development database. Some of the good distributed source code control systems do this now.

Here’s a good example of what I mean:

http://github-images.s3.amazonaws.com/blog/2011/mac-screenshots/commits-full.png