Don Burleson: The Index Rebuild Debate

OK Don, technical issue number 1.

In my Index Rebuild presentation you seem to have taken exception to
(www.actoug.org.au/Downloads/oracle_index_internals.pdf) , I mention a
couple of quotes of yours.

First quote:

"Note that Oracle indexes will spawn to a fourth level only in areas of the index where a massive insert has occurred, such that 99% of the index has three levels, but the index is reported as having four levels."

This comes from an article that you Don, yes you, wrote and promoted in this very newsgroup in the "Index Rebuilding" thread in January last year
(http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&th=6bf6a5904b3a2189&seek
m=o%25WZ9.61302%24c41.1415158%40news2.telusplanet.net#link1)

I suggest in my presentation that this is utter rubbish and a silly Oracle myth. So please Don, explain why you are correct and I'm so wrong. Don, explain how an Oracle B*tree index can become unbalanced in the manner you describe. Supply us with evidence, a test case, just one example of where this is possible. It's your claim Don, come on, prove it. If you wish, you can even make reference to the quote that Niall mentions in his excellent post where you make exactly the same claim.

While doing so, you may also want to explain why all your posts in that thread and most of your others have subsequently disappeared from the archives? It's all very odd isn't it ? Why have they been removed Don, you' re not trying to hide something are you ? I've asked this of you in the past with no response, perhaps you might want to take this opportunity to explain yourself now ?

Second quote:

"If the index clustering is high, an index rebuild may be beneficial"

This comes from your "infamous" Inside Oracle Indexes article
(http://www.dbazine.com/burleson18.shtml).

I also suggest in my presentation that this is utter rubbish and another Oracle myth. So again, please Don, explain why you're correct and why I'm so wrong. Don, explain why on earth if you have a high CF, you would consider an index rebuild. Supply us with evidence, a test case, just one example of how the CF changes after a rebuild. I strongly suggest to you Don that near the end of your presentation (point 2) where this quote originates that your entire discussion is absolute rubbish. Completely wrong. Because Don, if you delete "all people whose last_name begins with the letter K", the result on the index would be *exactly the same regardless of the CF*. Prove me wrong Don, please do. And if the CF doesn't change Don, and the rebuild criteria remains the same afterwards, please Don what was the purpose of the rebuild if the index simply needs again to be immediately rebuilt ? Don, please show your Oracle Guruness and explain yourself. And please, play fair and debate the issue *before* you go and change the article again.

The floor's all yours Don, debate away .

Or would you rather nibble on some cheese ? Squeak Squeak.

Richard Received on Tue Jun 08 2004 - 07:56:46 CDT