Re: Shared Memory and Semaphores

From: sybrandb <sybrandb_at_gmail.com>
Date: 10 Apr 2007 08:59:27 -0700
Message-ID: <1176220767.746867.199390@q75g2000hsh.googlegroups.com>

On Apr 10, 7:30 am, "peter" <hhh.datab..._at_gmail.com> wrote:
> On Apr 10, 10:17 am, sybra..._at_hccnet.nl wrote:
>
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> > On 9 Apr 2007 22:03:55 -0700, "peter" <hhh.datab..._at_gmail.com> wrote:
>
> > >I have doubt in both of these.
> > >Don't you think oracle is taking to much shared memory and semaphores
> > >are on these server.
> > >It's a test server, there so many databases are here on it.
> > >Please provide any link, which can help me to find that how much
> > >shared memory and semaphores are good for current databases.
>
> > How about reading the friggin manual?
> > You know, that book you consistently refuse to read!
> > The #1 reason why you are asking RTFM questions for more than a year
> > now!
> > There is a formula for the # of semaphores, and IIRC, it is in the
> > documentation.
> > Obviously, you also shouldn't allocate all available physical RAM to
> > SGA.
> > But you are so lazy, you don't specify the amount of physical RAM, and
> > you leave it to this group, to calculate the total amount of SGA you
> > have allocated. You don't even feed the results of the ipcs command
> > through awk to do this yourself. Probably because you don't know Unix
> > and don't want to read about it either.
> > Aren't you getting ashamed of yourself?
>
> > --
> > Sybrand Bakker
> > Senior Oracle DBA
>
> Total RAM is 16G with 2 processes. It is Sun Solaris. Database is
> 9.2.0.3
> It has 25 different-2 databases.
> Please tell me any manual which can tell how much semaphore or shared
> memory can be acceptable for any particular reason.- Hide quoted text -
>
> - Show quoted text -

How about reading the installation manual for Sun Solaris? Sounds pretty obvious, doesn't it? From you I get the impression all DBAs nowadays are completely clueless, and more experienced DBAs should spoon fed them with almost everything. Nowdays DBAs

a) don't know Oracle
b) don't know Unix
c) don't have a clue on O/S technology

I wonder how you got this job. Because you could spell Oracle? Or because your management is even more clueless on Oracle?

To grasp whether what you are doing is sensible just pipe the results of ipcs through awk, with the following code awk '/^m.*oracle.*/{sum=sum+$NF} END {print sum}' end be amazed at the stupid decision to allocate so much memory for way too many databases on one single server. Then go to the back door, open it, go home and never return. You are NOT a DBA, nor will you ever become one. You are just too stupid and too lazy for this job.

--
Sybrand Bakker
Senior Oracle DBA

Received on Tue Apr 10 2007 - 10:59:27 CDT