Re: 9i's dynamic sga

From: Howard J. Rogers <dba_at_hjrdba.com>
Date: Sun, 23 Jun 2002 09:04:02 +1000
Message-ID: <af2vq8$beh$1@lust.ihug.co.nz>

Yup.

Set SGA_MAX_SIZE to X, and Oracle nabs the whole of X from the O/S, even if then doesn't go on to allocate all of X to the various components of the SGA. The 'show SGA' command then displays what has been reserved, not what is actually in use (which is a shame, I think, but you leanr to live with these things).

It has to be this way (the reserving, not the displaying), because when you dynamically increase the buffer cache or shared_pool, the granule allocations have to be contiguous allocations of memory -contiguous, that is, with what was already there.

Regards
HJR "sg" <s4v4g3_at_europe.com> wrote in message news:3D14FFD2.2040303_at_europe.com...
> Does anyone know if no matter how we set the shared pool and db cache
> Oracle's memory consumption at OS level will always equal to
> sga_max_size? I set a pretty low db cache and shared pool and a large
> sga_max_size and when I do show sga it actually syas that the
> sga_max_size sga is allocated. Does Oracle reserve sga_max_size memory
> at OS level since instance startup?
>
Received on Sat Jun 22 2002 - 18:04:02 CDT