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Re: LMT advice

From: Howard J. Rogers <howardjr2000_at_yahoo.com.au>
Date: Fri, 26 Sep 2003 06:29:54 +1000
Message-ID: <3f7350fa$0$6529$afc38c87@news.optusnet.com.au>

Daniel Morgan wrote:

> foolishHurts wrote:
> 

>>We are looking at LMT (finally) and I find two options: Autoallocate
>>and uniform.
>>
>>I find with autoallocate, we are seeing truely huge amounts of extents
>>(2000) of very small size (100 KB). While 100 KB seems reasonable for
>>small tables, for large tables I would expect extent sizes in the MB
>>range.
>>
>>Question:
>>Which is better and why: Uniform (one large, one small) or
>>Autoallocate (and ignore extents)?
>>
>>Also, I can not find the old note where I stored the archive location
>>for this newsgroup, so please post that address as well.
>>
>>Thanks!
>>
>>Evan
>>
>>Currently on 8.1.7.4, heading for 9.x as fast as we can drag our
>>vendors and customers. <GRIN>
>>
>>
> Use UNIFORM ... it eliminates tablespace fragmentation.
> 
> Archive can be viewed through google.com.
> 

So does using autoallocate, since even if it gives you a 1 MB extent, it's handled by actually allocating you multiple 64K 'subextents'.

There is no reason I can think of not to use autoallocate.

Note to the original poster: since autoallocate only ever allocateds 64K, 1M, 8M and 64M (and 256M) extents, I'm not entirely sure how you managed to get 100K extents. Also, the algorithm really will start scaling up the extents' size to prevent the allocation of thousands of small extents. So whatever it is you've done, it isn't autoallocate!

Regards
HJR Received on Thu Sep 25 2003 - 15:29:54 CDT

Original text of this message

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