Compulsive Tuning Disorder…


I can’t remember where I first heard the phrase “Compulsive Tuning Disorder”, but it was mentioned again at ORCAN recently. I guess my approach to the database is almost the opposite of that. Maybe “Compulsive Non-Tuning Disorder”.

When you’re reading the blog posts on the internet you could be forgiven for thinking that every Oracle database is a massive, high performance, 24X7, mission critical system. We all tend to write about interesting systems and issues, but these don’t necessarily reflect the reality of most DBAs day to day jobs.

I would hazzard a guess that most installations out there would run just fine with default settings and very little intervention.

Why do I mention this? I get lots of questions from people who are running very ordinary systems but are expending massive amounts of energy on pointless tuning because they read the latest article by person X, Y and Z.

Am I saying you don’t need to know about more detailed stuff? Of course not. The more you know, the easier it is to deal with a real performance problem when it occurs. The trick to being a good DBA is knowing how to focus your effort. Don’t obsess about minute details on humdrum systems. Your time would probably be better spent teaching the developers how to write better SQL and PL/SQL. That would probably have a more profound impact on database performance than the constant pointless tweaking.

Enough of my random ramblings for today… 🙂



Author: Tim...

DBA, Developer, Author, Trainer.

8 thoughts on “Compulsive Tuning Disorder…”

  1. I remember reading about “Compulsive Tuning Disorder” (CTD ) in Oracle Insights co-written by Gaja Vaidyanatha. In case you have not read the chapter, I would recommend it..not only for technical knowledge but also to enjoy Gaja’s humorous style of writing 🙂


  2. Tim – sorry; you didn’t hear about CTD from me during the Orcan conf. First, I definitely didn’t refer to it. But more important, I sort of don’t agree with the concept in general: so you surely didn’t hear me mentioning it. Why I don’t agree? Well, that’s for another day. But I tend to think along the same lines you mention in this blog.

  3. Hi.

    I could have sworn it was you who mentioned it, but I must be wrong. I’ve removed your name from the post. 🙂

    I wasn’t suggesting you suffer from CTD. Whoever said it was referring to it as being the wrong thing to do, so sort-of agreeing with me. 🙂



  4. …and if you’re still using those customized settings you set in Oracle7 in your current 10g system — you really need an intervention 🙂
    Heck, the first thing I do nowadays is go through the settings and rip out 80% of them, since the 10g defaults are usually much better.

  5. Totally agree about the ‘focus” point. Every production database had dozens (and more) performance issues that could be fixed, but DBA should be able to find issues that cause the problem he is adressing.

    One of the methods I use is a combination od SQL and wait event based spike analysis that is applying clustering algorithm towards different aspects of database performance across SQL wait sibmetrics and different wait events (incuding ones that are RAC related). Resulting chart is 10x better than any report and enables to see issues and how they develop across timelines and RAC nodes.

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