Re: Disappearing Sessions - Can Code Alone Cause It?

From: Dereck L. Dietz <dietzdl_at_ameritech.net>
Date: Wed, 27 Feb 2008 23:43:16 GMT
Message-ID: <oAmxj.14083$Ej5.5696@newssvr29.news.prodigy.net>

"joel garry" <joel-garry_at_home.com> wrote in message news:57f49101-288d-4a26-a379-ce3b2ae68746_at_34g2000hsz.googlegroups.com... On Feb 27, 2:29 pm, "Dereck L. Dietz" <diet..._at_ameritech.net> wrote:
> "Mark D Powell" <Mark.Pow..._at_eds.com> wrote in
> messagenews:934bfb09-31fe-4248-9a17-768efca843c6_at_k2g2000hse.googlegroups.com...
> On Feb 27, 5:00 am, "Dereck L. Dietz" <diet..._at_ameritech.net> wrote:
>
> > Oracle 10.2.0.3.0
> > Windows 2003 Server
> > 16GB Memory (93% SGA( 93% Buffer Cache,<3% Shared Pool, <3% Large Pool),
> > 7%
> > PGA)
>
> > Our off-site DBA is saying our code is causing the disappearing sessions
> > because, to paraphrase him: that's the database it has to run in. That's
> > why hes telling us to do things like incremental commits.
>
> > My question is: can code alone cause sessions to sometimes run to
> > completion but other times just disappear without a trace?
>
> > I have a feeling he's trying to make us do work-arounds rather than
> > trying
> > to get to the actual root cause of this problem.
>
> I am not sure I understand the memory percentages you posted but if
> the PGA is 7% of the 16G and the SGA is 93% then the PGA is probably
> way too small. Plus some memory should be left for the OS and the
> posted numbers do not show it.
>
> What kind of database is this (OLTP, Warehouse, DSS, OLAP)?
>
> Are there error messages in the alert log related to the "disappeared"
> sessions? Are there trace files in the udump destination?
>
> There should be clues. Is connection pooling in use?
>
> HTH -- Mark D Powell --
>
> === Here is the memory breakdown
>
> Total 16GB of memory on server
>
> Total allocated to Oracle 12,800GB allocated as follows:
>
> SGA - 93.75% (12000MB)
> o shared pool - 3.5% (416MB)
> o buffer cache - 94.3% (11312MB)
> o large pool - 0.4% (48MB)

http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/memory.htm#i52838 Do you know how much memory your sessions need? What are your sort init.ora parameters?

> o java pool - 1.3% (160MB)
> o other - 0.5% (64MB)
>
> PGA - 6.25% (800MB)
jg

--
@home.com is bogus.
http://www.antsight.com/zsl/rainbowcrack/index.php


I'm not sure of the memory for sessions.  I'll have to determine that 
tomorrow when I have access to the database. 
Received on Wed Feb 27 2008 - 17:43:16 CST

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