By using this site, you agree to our updated Privacy Policy and our Terms of Use. Manage your Cookies Settings.
438,321 Members | 1,206 Online
Bytes IT Community
+ Ask a Question
Need help? Post your question and get tips & solutions from a community of 438,321 IT Pros & Developers. It's quick & easy.

Oracle on NT4 memory use

P: n/a
We upgraded a server from 512MB to 2.5GB due to performance issues. The
server still uses ca. 512MB of physical memory. The total commit charge is
1.8GB. Physical Memory available is about 2GB.

I've read about NT's 2GB/2GB problem, but I am not sure whether that is the
cause.

The main problem are most likely inefficient queries, but I would like to
maximize Oracle's memory use in the mean time. If I see 2GB of RAM free, I
would like to put them to use.

Any ideas?

Thanks,

Holger

Jul 19 '05 #1
Share this Question
Share on Google+
3 Replies


P: n/a
"Holger Knust" <kn****@bellsouth.net> wrote in message news:<TZ*****************@fe02.atl2.webusenet.com> ...
We upgraded a server from 512MB to 2.5GB due to performance issues. The
server still uses ca. 512MB of physical memory. The total commit charge is
1.8GB. Physical Memory available is about 2GB.

I've read about NT's 2GB/2GB problem, but I am not sure whether that is the
cause.

The main problem are most likely inefficient queries, but I would like to
maximize Oracle's memory use in the mean time. If I see 2GB of RAM free, I
would like to put them to use.

Any ideas?

Thanks,

Holger

You won't be able to use the 2G. By design NT uses 50 percent of the
memory for O/S purposes. Hence Oracle recommends to use only 1/3 of
physical memory for the SGA. See the relevant documents on NT
architecture on Metalink.
You should address the root cause instead of fighting symptoms.
Generally speaking increasing the size of the SGA also increases
paging and swapping. All Oracle hitratio's 99 percent and your OS will
be suffocating.

Sybrand Bakker
Senior Oracle DBA
Jul 19 '05 #2

P: n/a
My next question would be: SGA 1/3 of the physical memory available (2.5GB)
or 1/3 of 500MB that NT leaves to apps?

I will go after the queries but that will take some time.

Thanks,

Holger

<sy******@yahoo.com> wrote in message
news:a1*************************@posting.google.co m...
"Holger Knust" <kn****@bellsouth.net> wrote in message

news:<TZ*****************@fe02.atl2.webusenet.com> ...
We upgraded a server from 512MB to 2.5GB due to performance issues. The
server still uses ca. 512MB of physical memory. The total commit charge is 1.8GB. Physical Memory available is about 2GB.

I've read about NT's 2GB/2GB problem, but I am not sure whether that is the cause.

The main problem are most likely inefficient queries, but I would like to maximize Oracle's memory use in the mean time. If I see 2GB of RAM free, I would like to put them to use.

Any ideas?

Thanks,

Holger

You won't be able to use the 2G. By design NT uses 50 percent of the
memory for O/S purposes. Hence Oracle recommends to use only 1/3 of
physical memory for the SGA. See the relevant documents on NT
architecture on Metalink.
You should address the root cause instead of fighting symptoms.
Generally speaking increasing the size of the SGA also increases
paging and swapping. All Oracle hitratio's 99 percent and your OS will
be suffocating.

Sybrand Bakker
Senior Oracle DBA


Jul 19 '05 #3

P: n/a
"Holger Knust" <kn****@bellsouth.net> wrote in message news:<Wz*****************@fe03.atl2.webusenet.com> ...
My next question would be: SGA 1/3 of the physical memory available (2.5GB)
or 1/3 of 500MB that NT leaves to apps?
That sounds very weird. You sure you tuned NT for application server?
Looks like you left it at file server, then it uses up as much
mem as it can for file cache. You running Server, aren't you?
Not Workstation! And SP6?
You should have a LOT more than 500Mb free to apps in app server
mode.

I will go after the queries but that will take some time.

Good luck.
Cheers
Nuno Souto
wi*******@yahoo.com.au.nospam
Jul 19 '05 #4

This discussion thread is closed

Replies have been disabled for this discussion.