Author: Christo Kutrovsky

Aligning ASM Disks on Linux

Linux is a wonderful operating system. However there are a number of things that one needs to do to make sure it runs as efficiently as possible. Today, I would like to share one of them. It has to do with using ASM (Automatic Storage Manager) disks.

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Pythian Goodies: Oracle Parallel Basics

In this new installment of Pythian Goodies Doug Burns discusses Parallel Basics. This video is a good introduction to using Oracle Parallel features and most importantly, what problems you may have with it.

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Pythian Goodies: Oracle Disk I/O Basics

Two weeks ago, I released a video about Flash Recovery Area as part of the Pythian Goodies project. Here is the next video in the sequence, Oracle I/O Basics.

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Sequences in Oracle 10g RAC

I got a call from a developer who had a table with a primary key populated by a sequence, a timestamp column with the current date and some other columns. He had a specific set of data that, when ordered by the primary key had out of order timestamps. He was puzzled how this could be. We changed the sequence to “ordered” and increased the cache to 1000. Now selecting on either node gets the next number as he expected. I warned him that there would be some performance implications due to cluster synchronization. Him being a responsive developer, asked me what the impact would be, so I tested it out.

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Pythian Goodies: Oracle Flash Recovery Area

On Friday, I announced the Pythian Goodies project, and now here it is, the very first video of the series. The topic is “Flash Recovery Area,” and how can it make your life easier.

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Announcing Pythian Goodies

I’ve been wondering for a while now how best to transfer knowledge efficiently and in a fun way. Presentations are good, but they require a lot of effort in preparation and research, and they are not as interactive as they could be when the group is smaller. To answer some of these issues, I would like to introduce you to Pythian Goodies. What is a Pythian Goody session you ask? Find out here.

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Oracle RAC Cache Fusion Efficiency: A Buffer Cache Analysis

Many people would like to know how well their application will run in RAC. Would it be faster or slower? Would it run at all? Well, I have a query that can answer that question. There’s a caveat however. You have to first put your application in RAC, then the query can tell you how well it runs.

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Oracle Support Case Studies

As I was poking around metalink, I found the following extremely interesting section. It’s in a very obvious place, but it’s new, so many of you may have not noticed it. It’s called “Support case studies” and provides some amazing articles.

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Oracle Patch 10.2.0.3 – Bugs We’ve Seen

When I read Note: 391116.1 with the full list, I noticed the following bugs that we’ve encountered are fixed. Unfortunately, an important bug in 10.2.0.2 posted on the Sept. 29 is not listed as fixed in this patch list.

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Diagnosing Oracle Performance Problems on *nix

One day I came up with the following neat idea. Start a second listener, on a different port, calling it the emergency listener. Then renice the listener process with higher priority. Now, every time I connect to the database via my emergency listener, my connection gets higher priority, and thus feels like there’s no problem with the database’s resource use.

There is one little caveat however. You need to either have access to root, or have a nice SA that will add renice to your sudoers file .

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