[askdba] Re: Question regarding MAX SGA Size and Physical Memory
- From: Rajesh Puneyani <rajpuneyani@xxxxxxxxx>
- To: askdba@xxxxxxxxxxxxx
- Date: Thu, 28 Oct 2004 09:23:08 -0400
Hi Yavor,
I was out for a few days hence I could not reply to this.
Thanks for this information. Let me ask another question regarding this -=
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How about following configuration (irrespective of 2Gb limit or 3Gb). ....
assign=20
75% to SGA_MAX_Size
15% to PGA
10% Oracle Executables + Binaries etc (like you mentioned)
This way for a 2 Gb limit, we have 200 Mb for EXEs/Binaries and Bad Pointer=
s.
Do you (or anyone else in this forum) see any problems with this
configuration ?
Ankur/Ganesh/Others ...Pls. give your expert comments on this ?
Thanks everyone for their contribution.
On Tue, 26 Oct 2004 08:57:15 +0300, Yavor Ivanov <yavor_ivanov@xxxxxxxx> wr=
ote:
> First of all, if you have 4 GB RAM you can easily use 3 GB for Ora=
cle
> (Note:1036312.6). In fact, you can use even more with AWE (Note:225349.1)=
,
> but in your case it is not needed.
>=20
> 1. If your process space is limited to 2 GB (and it is, if you do =
net set
> the 3 GB switch of Windows), you cannot have 2 GB SGA. Your _whole_
> process space is 2 GB. This is SGA + PGA + Oracle executables and
> libraries (~50 MB). And, in fact, Windows reserves the first and last 64 =
K
> of that 2 GB windows to catch bad pointers. So you never have exact 2 GB.
> Remember, the SGA is allocated in granules (16 MB each, in your case), so
> you cannot allocate (2GB - 128K)
>=20
> 2. No. Note 148495.1 stat=D0=B5s:
> "At instance startup the Oracle Server allocates the granule entries, one
> for each granule to support SGA_MAX_SIZE bytes of address space."
> So Oracle will try to allocate 2 GB, no matter if you use 128 MB o=
r 2 GB
> for all pools.
>=20
> Rgds,
> Yavor
>=20
> On Mon, 25 Oct 2004 17:07:32 -0400, Rajesh Puneyani
>=20
>=20
> <rajpuneyani@xxxxxxxxx> wrote:
>=20
> > Hi guys,
> >
> > We are on windows 2k / oracle 9iR2.
> > One of my database has following configuration -
> >
> > SGA_MAX_SIZE =3D 550 Mb
> > SIZE of SGA =3D 550 Mb
> > LOCK_SGA =3D FALSE
> >
> > This has to be a dedicated database on this server (with 4Gb RAM). so
> > whole 2Gb can be dedicated to this one database.
> >
> > 1. Now If I shutdown this database, change the parameter SGA_MAX_SIZE
> > =3D 2Gb then can I expect any issues while restarting the database ?
> >
> > 2. If LOCK_SGA is false then Step 1 would not have any effect on
> > ACTUAL SGA Size..Right ? Pls. confirm.
> >
> > Your insight on this would be highly appreciated.
> >
> > Thanks and Regards
> > Rajesh
> >
> >
>=20
>=20
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>=20
>
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