Re: Index management

Daniel Morgan wrote:

> Roger S Gay wrote:
>

>>>> By definition the order of rows in a relational table is random.
>>>
>>>
>>> Also absolutely true.
>>>
>>
>> Howard, are you sure of this? Relational theorists please correct me 
>> if I am
>> wrong, but I thought the best we could say about the order of rows is 
>> that
>> it is indeterminate, which means we can't even make statistical arguments
>> based on assumed randomness.

No, the problem is intervention by people who don't know what the point of this thread is.

Imprecision in the use of the word "random" is not the issue.

The issue is "should I rebuild my indexes". And moving on from that, "how do I know if an index should be rebuilt". That is all. Everything else is just so much navel-gazing.

Mike Ault claims he has a ratio which tells you when an index should be rebuilt. That ratio is built on one number we can't quite work out what he means. And another number, the clustering factor, which we all know presicely what it means.

Either that ratio is a load of old nonsense, or it isn't. That's all you have to be precise about. True or false. Black or White. Right or Wrong.

All Mike has to do is to show us how to calculate this ratio, and show us the ratio improving after an index rebuild (NOT an index redesign).

That's all. It isn't rocket science. And it isn't very difficult. And it's not at all imprecise.

> I know that both
> Mike and Howard know that what you said is correct. And both undoubtedly
> will respond with "that is what I meant."

Bzzt. I replied, and reply, that I couldn't give a monkeys whether its random or indeterminate or painted bright blue and playing Knees Up Mother Brown on the harpsichord. It *doesn't* *actually* *matter*.

> But it may well be that much
> of this dispute is the fact the words are being thrown around without
> the clarity that would be provided by the demos we are asking for.

No, the dispute is: can you give me a ratio that tells me when to rebuild an index?

Not when one of the components of that ratio is a number which is invariant when rebuilding, you can't, is my reply.

It is a simple enough dispute.

> Mike, for example, must be able to quickly and easily determine whether
> a clustering factor is altered by a rebuild. The fact that he continues
> to repeat his statement indicates to me that we likely have more
> sloppinless of language than sloppiness of code. Problem is we have yet
> to see that code.

This I will grant you. If Mike keeps stating something when the simplest of test proves the contrary, he either is merely obtuse, or he is talking about something we mere mortals aren't.

We have already seen this, in fact, when Mike subtley shifts the meaning of the words "rebuild an index" to actually encompass "drop index X... create index newX".

So maybe there is something else there he hasn't yet explained, and it would do us all a lot of good for him to so explain it. That is indeed true.

> Which is a point to which I will agree and I suspect Howard will too.
> That it appears that Mike does not is what I would like to see resolved
> in this thread if we can just stick to Oracle and not personal insults.

I truly wish you would call a spade a spade. It is insulting, frankly, to be accused of not discussing technical points. Which you do by your "equanimity" in such comments.

>
> Let the entertainment continue.
>

It isn't entertainment. This is factual science, pure and simple. Either Mike knows what he's talking about; or he's not talking about it very clearly; or he doesn't. There are not many other possibilities.

If you find that fun, so be it. Personally, I find it immensely irritating that the *knowledge* element of this is having to be spelled out as if for the first time.

Regards
HJR Received on Sat May 08 2004 - 22:43:55 CDT