Re: Oracle8i MTS on NT - any experience?

If you are considering MTS you will want to define a large pool, in addition to the shared pool. This is where the MTS memory will go if one is defined.

The amount per session memory is based upon the application, not any fixed number. I don't have it in front of me, but I think it is just a sum of the uga of all sessions/num of sessions will give you a good starting point.

I have 1200 connections to a 14G 14CPU sun box. My total shared pool is around 1.9G

375M to shared pool, 768M to large pool, and the rest (65,000 buffers) to the db_block_buffers
I could easily reduce my shared pool down to 250M, now my large_pool sits around 500M used. Most connections us a very little bit, but about a third of them use 2-10M of memory. Others can grow, so I have a lot of breathing room. Most of that memory is due to PL/SQL table's that are used constantly.

--
Robert Fazio
Senior Technical Analyst
dbabob_at_yahoo.com

"Alex Filonov" <afilonov_at_pro-ns.net> wrote in message
news:3B4E615F.1BBC4EBB_at_pro-ns.net...


> Paul Offord wrote:

>

> > Just for background - the database server is an IBM NetFinity with 8

> > processors and 4GB of RAM.  We are running the NT 4GT option to give us

 3GB


> > of application memory.  At 100 users (around 250 connections) the

 processors


> > are busy but not stressed.  Total memory in use by the Oracle process

 hovers


> > around the 2GB mark on PerfMon.

> >

> > Best regards...Paul

> >

> > Paul Offord <paul.offord_at_btinternet.com> wrote in message

> > news:9iifsa$4nv$1_at_plutonium.btinternet.com...

> > > I am currently helping a customer to troubleshoot some Oracle

 Financials


> > > post-installation problems.  At the core of the system they have an

 Oracle8i


> > > database running on an NT4 server.  Oracle financials seems to require

 2
 or


> > > sometimes 3 database connections per server.  The system needs to

 support


> > > 400 users and so we are expecting 1,000 connections to the database

 server.


> > > Oracle consultants have been on site and tuned the per connection

 memory


> > > requirement down to 5 MB.  However, that would still require 5GB -

 beyond


> > > the capabilities of NT.

> > >

> > > We are looking at implementing Multi-Threaded Server to bring the

 memory


> > > demands within the capabilities of the NT platform.  Oracle UK's

 experience


> > > of an NT site of this size seems limited.

> > >

> > > *  What experience do you have of MTS on NT?

> > >

> > > *  Do you run an Oracle8i server on NT with a similar number of users?

> > >

> > > Any experiences, war stories, dos/don'ts would be much appreciated.

> > >

> > > Tnaks in advance...Paul

> > >

> > >

> > >

> > >

>

> How big is your SGA right now? To use MTS, you'll have to increase SGA

> significantly, at least by 1m per user session. For 400 connected users

 you are


> going to need 400M extra in shared_pool_size. Can you do it? Max SGA

 should be


> about 2G in your case, don't know for sure. Increase of shared_pool_size

 is


> needed because when using MTX, private SQL areas are allocated within

 shared


> pool. My experience with MTS on HP-UX (32-bit) wasn't particulary good,

 because


> maximum for all shared memory areas is 1.7G in this case, and with 1200

> sessions it wasn't possible to have enough shared pool.

>