Re: Suggestions for first exam ...

From: Howard J. Rogers <howardjr2000_at_yahoo.com.au>
Date: Sat, 27 Sep 2003 18:47:15 +1000
Message-ID: <3f754f56$0$5000$afc38c87@news.optusnet.com.au>

Sybrand Bakker wrote:

> On Sat, 27 Sep 2003 10:32:31 +1000, "Howard J. Rogers"
> <howardjr2000_at_yahoo.com.au> wrote:
>

>>
>>There really is a lot of either (a) nonsense or (b) loose talk made about
>>indexes.
>>
>>You do *not* need to rebuild an index to 'get the tree ... balanced',
>>because Oracle's indexes are *always* balanced. In real time, every time.

>
> Sure, adding extra levels, that is.
>
> A recent rebuild freed up 5 (FIVE) G of space, on a server, where
> space is at premium, and no extra disks can be added.
> So, what should we have done? Reading your comments, and never rebuild
> anymore? Try to convince a customer to replace a server?
> And just for the record: the application involved was Oracle
> Financials, where due to the nature of the application the majority of
> the indexes skew.
> I'm not sure whether you really can judge the situation everyone is
> in. Yet you seem to pretend you can. I would rather suggest you would
> stop making such absolute comments, which in our situation don't make
> sense at all. We *HAVE* to rebuild indexes. PERIOD.
>
>
>
> Sybrand Bakker, Senior Oracle DBA
>
> To reply remove -verwijderdit from my e-mail address

Come off it, Sybrand. You "have" to rebuild... for FIVE gigabytes? You're kidding, right?

I had to read your post again, just to make sure you weren't talking about terabytes. But no, you said gigabytes, and you seem to seriously feel that reclaiming five gigabytes is something worth embracing massive I/O and exclusive table locks for.

And why in God's name would I want to convince a customer to "replace a server" when all that is actually needed, it would seem, is a bit more disk space??

And yes, I would convince the customer to buy that disk space, because I could show them the costs of rebuilding, versus the rather pathetic benefits.

And no, I wasn't being absolutist. I'm being realistic. Read my original post again. I made provision for rebuilding indexes built on sequences where you do occasional light-weight deletes.

Tom Kyte says don't rebuild. Connor McDonald says don't rebuild. I say don't rebuild, much. Sybrand says lots of things, most of them quite rude to newbies, including "I need my 5 gigabytes back!".

I'll let others judge which is the more appropriate course of action.

And, just for the record, Oracle indexes do NOT skew. Period.

Regards
HJR Received on Sat Sep 27 2003 - 03:47:15 CDT