Re: Experts only: Extent sizes

Peter Moore wrote:
>
> schluete_at_deneb.informatik.uni-hannover.de (Axel Schlueter) wrote:
>
> > whenever I try to create a table with INITIAL = 16K, Oracle allocates extents
> > with 20K. My blocksize is 2K, I got this behaviour on ORACLE 7.1.3 and 7.3.2.
 

> > As far as I see, Oracle always allocates multiples of 5 Blocks, but I haven't
> > found anything in Oracle's documentation or white papers.
 

> > Any suggestions?
>
> I remember being told about this on Oracle's DBA course. AFAIR, the
> INITIAL extent will always be a minimum of 10 blocks, but NEXT and
> subsequent extents can be any multiple (including 1) of your
> blocksize. That's if I remember it right!
>
> So if you do INITIAL 1K NEXT 1K and force the segment to extend,
> you'll use 22K of space; 20K (10 blocks) initially and then 2K (1
> block) as a next extent.
>
> Yep, it's a feature - it's probably documented *somewhere* but I
> couldn't tell you where!!
>
> Cheers,
>
> Pete
> --

One place is in the Oracle7 Server Concepts Manual (V7.3). Page 3-13.

-- 
Roderick Manalac					rmanalac_at_oracle.com
Oracle Corporation                                  Insert witty quote
here

DISCLAIMER:  The views expressed here do not necessarily represent
             the views of my employer.