Re: Locally Managed Tablespaces

  • From: Niall Litchfield <niall.litchfield@xxxxxxxxx>
  • To: ganstadba@xxxxxxxxxxx
  • Date: Thu, 20 Jan 2005 20:48:49 +0000

On Thu, 20 Jan 2005 15:19:00 -0500, Michael McMullen
<ganstadba@xxxxxxxxxxx> wrote:
> why not use system allocation sizes?
> extent management local autoallocate
> If tables are going to be a variety of different sizes this should work
> fine. I use it pretty much everywhere because no one ever has any idea how
> big their tables will get.

Do you try predicting extent growth/free space availability for
segments and if so how do you do it? I have found no way to reliably
predict what size the next extent will be - let alone the next say 5. 
check out the ask tom discussion at
(will wrap) and note that Tom lists the pattern he observes but that

it is subject to change without notice and
sometimes you get different results. 

I guess my bias is that I really, really don't care how many extents
my segment has (at least if I did have tens of thousands i'd be
worrying about partitioning instead) and so I see no reason to use

> You danger, no matter what you do is the originator will throw out some
> wacky initial extent size, like 10Gb and only have one row. Oracle will go
> with their inital but ignore the next.

I agree, but this is surely best managed using some sort of change
management system rather than any software policy.

Niall Litchfield
Oracle DBA

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