Inside the Oracle Optimizer - Removing the black magic: Upgrading from Oracle Database 9i to 10g: What to expect from the Optimizer

Tuesday, February 26, 2008

Upgrading from Oracle Database 9i to 10g: What to expect from the Optimizer

One of the most daunting activities a DBA can undertake is upgrading the database to a new version. Having to comprehend all of the new features and to deal with potential plan changes can be overwhelming. In order to help DBA's upgrade from Oracle Database 9i to 10g a new whitepaper called "Upgrading from Oracle Database 9i to 10g: What to expect from the Optimizer" has recently been posted on Oracle Technology Network (OTN). This paper aims to explain in detail what to expect from the CBO when you upgrade from Oracle database 9i to 10g and describes what steps you should take before and after the upgrade to minimize any potential SQL regressions. This is a must read for any DBA planning on upgrading from 9i to 10g in the near future!

1 comment:

Unknown said...: Thanks! I also appreciate the parts on the diff stats. This is a great feature to have back-ported to 10.2.0.4. Thanks again!; February 28, 2008 at 9:34 AM

Subscribe to: Post Comments (Atom)

Upcoming events & presentations

Oracle Open World, the largest gathering of Oracle customers, partners, developers, and technology enthusiasts will happen October 2-6 in San Francisco. Of course the Optimizer development group will be there and you will have multiple opportunities to meet the team, in one of our technical sessions, or at the Oracle demogrounds.

This year the Optimizer team has 3 technical sessions;

Monday, October 3rd at 12:30pm our hands on lab, Oracle Optimizer: Prevent Suboptimal Execution Plans
Session 29380 at the Marriott Marquis - Salon 12 / 13
In this hands on lab you will get an opportunity to solve 4 SQL tuning problems either on your own or with the help of the Optimizer development team. The problems will include scenario like, why was my index not selected, why statistics were ignored, and many more.

Wednesday, October 5th at 10 am Oracle Optimizer: Best Practices for Managing Optimizer Statistics
Session 13961 at Moscone South - room 103
In this session we will discuss the features introduced in Oracle Database 11g to improve the quality and efficiency of statistics-gathering as well as strategies for managing statistics in various database environments.

Thursday, October 6th at 12 noon Oracle Optimizer: Tips for Preventing Suboptimal Execution Plans
Session 14069 at Moscone South - room 104
This session is a continuation from a session we did last year called Top Tips for getting optimal SQL execution every time. This year we answers questions like why an index wasn't used, why partition eliminations did not occur, why statistics were ignored, and many more. With clear how-to examples, you will learn to identify and quickly resolve these issues without the need for optimizer hints or
initialization parameters.

If you have some burning Optimizer or statistics related questions, you can ask them at the Optimizer demo booth in the Database area of the demogrounds. Members of the Optimizer development team will be there Monday to Wednesday from 9:45 am until 5:30pm. The full searchable OOW catalog is on-line, or you can browse the speakers by name. So start planning your trip today!