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May 2012

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Here’s another one of those little changes that sidles in when you’re not looking.

When locally managed tablespaces first appeared, there were a number of posts on Usenet ( and the metalink lists (the OTN database forum didn’t exist at the time) about “missing” space in data files. The commonest sort of comment was along the lines of

“I’ve created a data file of 100 MB, how come I can only create 99 extents of 1 MB each?”

“I’ve created a data file of 10 GB, how come I can only create 9 extents of 1 GB each?”

Enkitec Extreme Exadata Expo

Enkitec Extreme Exadata Expo
Event date: 
Mon, 2012-08-13 - Tue, 2012-08-14

 August 13 – 14, 2012 
The Four Seasons Hotel & Resort, Irving, Texas

Enkitec Extreme Exadata Expo (E4)

Enkitec recently completed its 80th Exadata implementation, so this is a good time to announce that we are organizing the first Enkitec Extreme Exadata Expo (E4) on 13-14. August 2012, in Dallas, Texas!

Execution Plan Changes when the OPTIMIZER_FEATURES_ENABLED Parameter is Changed, But Why?

May 30, 2012 A question appeared on the OTN Database forums yesterday that has yet to receive an answer.  The question was essentially, why did the execution plan change when the OPTIMIZER_FEATURES_ENABLED parameter was adjusted from to, and why did the execution performance improve as a result of making the change?  A DBMS_XPLAN [...]

Fedora 17 and Oracle 11gR2…

Fedora 17 was released yesterday. I mentioned in a previous post I had run through the installation of Oracle 11gR2 on Fedora 17 alpha. With the arrival of the final Fedora 17 release I ran through the articles again last night to make sure everything was OK. You can see the finished versions here:

As always, installing Oracle on Fedora 17 is just for fun and totally not supported. For anything proper you should be using Oracle Linux or RHEL.



Cost of Virtual Indexes (Little Lies)

I’ve previously discussed Virtual Indexes and how they can be used to do basic “what if” analysis if such an index really existed. However, a recent comment on the OTN forums regarding using them to compare index costs made me think a follow-up post regarding the dangers of Virtual Indexes might be warranted. The big advantage of [...]

MOS is driving me crazy…

Why oh why can’t the My Oracle Support (MOS) website actually work like it is meant to?

I have been trying to get set up to use the new companies CSIs and it is driving me crazy. I’m on the “Support IDs and Privileges” page and I either get:

  • No buttons.
  • Some buttons, but not the one I need to request access to the CSIs.
  • A request access button, that doesn’t work.

I get the same random (mis)behavior on the HTML and Flash versions. I checked with another guy in the office and his account is doing the same thing, so it’s not an issue specific to my account. I’ve also tried on IE, Chrome, Firefox and Opera. No luck.

Can we please ditch these versions and have the old APEX version back? It’s wasn’t as pretty, but at least it worked!


For those not familiar with Richard Foote’s extensive blog about indexes (and if you’re not you should be) – the title of this note is a blatant hi-jacking of his preferred naming mechanism.

It’s just a short note to remind myself (and my readers) that anything you know about Oracle, and anything published on the Internet – even by Oracle Corp. and its employees – is subject to change without notice (and sometimes without being noticed). I came across one such change today while read the Expert Oracle Exadata book by Kerry Osborne, Randy Johnson and Tanel Poder. It was just a little throwaway comment to the effect that:

Understanding Linux Load Average – Part 3

In part 1 we performed a series of experiments to explore the relation between CPU utilization and Linux load average. We concluded that the load average is influenced by processes running on or waiting for the CPU. Based on experiments in part 2 we came to the conclusion that processes that are performing disk I/O […]

Third International NoCOUG SQL & NoSQL Challenge!

For anyone into using their SQL skills creatively, and getting out of the boring SQL-coding daily routine ... here is a puzzle that is both entertaining and challenging, and with a real prize for the winner!