OTN Mini Series "Understanding Parallel Execution"

As already announced previously OTN has now managed to publish my two part series called "Understanding Parallel Execution".

Part 1
Part 2

Thanks to Bob Rhubart from Oracle for his support in getting the articles published.

The articles should give you also an idea of what I cover in my "Mastering Oracle Parallel Execution" one day Oracle Expert seminar. More information can be found here.

New Version Of XPLAN_ASH Utility

A new version 2.0 of the XPLAN_ASH utility introduced here is available for download.You can download the latest version here.The change log tracks the following changes:- Access check- Conditional compilation for different database versions- Additional activity summary- Concurrent activity information (what is/was going on at the same time)- Experimental stuff: Additional I/O summary- More pretty printing- Experimental stuff: I/O added to Average Active Session Graph (more...)

Multiple Adverts

Just a couple of announcements:

1. I had the message already a couple of days added to the "Upcoming Public Appearances" sidebar on the right hand side of this page, now the official home page is available and registration open for the "CBO Days" at Trivadis 11th and 12th December in Zurich.

Join Mohamed Zait (Manager of the Query Optimizer Group at Oracle), Maria Colgan (Senior Principal Product Manager at Oracle), Jonathan Lewis, Jože Senegačnik, (more...)

DOAG 2012

This year again I'm going to present at the DOAG 2012 conference in November. Since it is a popular topic I decided to talk about "Cost-Based Optimizer Basics" there, too. According to the official schedule the presentation will take place on Thursday, the 22nd of November, "Raum 1" at 13:00.

Like last year, I'll also try to do some Unconference sessions in addition - if it is going to take place, which I don't know (more...)

Exchange Partition, Virtual Columns And Column Statistics

Here is an odd bug that can lead to some nasty side effects when using the EXCHANGE PARTITION technique. It is probably there for a very long time, simply because it depends on the usage of virtual columns, and the basic technique of virtual columns was introduced way back in the Oracle 8i times with the introduction of Function Based Indexes.

The problem isn't the exchange partition operation itself, but the accompanying swap of (more...)