dbi services Blog
Welcome to the dbi services Blog! This IT blog focuses on database, middleware, and OS technologies such as Oracle, Microsoft SQL Server & SharePoint, EMC Documentum, MySQL, PostgreSQL, Sybase, Unix/Linux, etc. The dbi services blog represents the view of our consultants, not necessarily that of dbi services. Feel free to comment on our blog postings.
OakTable at UKOUG 2012: Hybrid Columnar Compression (Exadata), SQL tuning, etc.
Yesterday, I went to a set of sessions organized by OakTable members just before the kick-off of the UKOUG conference 2012, one of the biggest events on Oracle Technology and E-Business in Europe. This post focuses on some of the covered topics, such as database development, Hybrid Columnar Compression (Exadata), optimizer statistics, and SQL tuning.
There were 2 streams with very interesting topics. I attended to sessions covering the following topics:
- Application development: Keep it simple
- Guiding practices for optimizer statistics
- Tuning SQL using profiles
The first session was not really technical, it was about best practices when it comes to database development. The main point is to not to think that simple equals easy: The goal is to write an application which will be maintainable. To do so, it is important to think about database design and not to focus only on one possible method.
The second session was about a new compression feature called Hybrid Columnar Compression is available on Exadata. It was very interesting because in some cases compression can be CPU killer feature. We also reviewed how basic and OLTP compression works.
After a quick lunch, we started again for the two last sessions.
The optimizer statistics are often a source of performance issues due to missing or bad statistics. However, developing a customized job is very time consuming and Oracle does the correct job for most of cases. The big advice is to let the default job and treat the exceptions.
The last session was about how using profiles to change plans without touching the code of an SQL statement. This Oracle feature is very useful when you quickly need to treat the symptoms because you have no time to solve the root cause. We had a look at how to create a profile with the tuning advisor and also by hand.
In conclusion, it was a very good introduction day with experts that were available to share their astounding knownledge!