Calculating Physical memory for Oracle Sessions

  • From: "Anurag Verma" <anuragdba@xxxxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Tue, 28 Nov 2006 21:28:09 -0600

Hi All,


My 9.2.0.7 database has an sga size of 1.3 GB and the RAM size is 4096 MB.

We were facing a problem of memory contention yesterday due to the increased
number of sessions/connections to the database.

96% of the Physical memory and 94-95% of virtual memory was used, when
checked the processes in the IBM AIX server.

So when the number of sessions increased, listener stopped receiving newer
connections.

The ever increasing number of sessions were taking up the memory.

Latch free contention was there and found library cache latch stats were
showing large number of sleeps.

If we need to increase shared pool, memory was not available.

One option we are planning is to increase the physical memory.


So my question is how do we determine the size of the memory used for Oracle
sessions.

Say for adding another 100 sessions, how much memory will it take, so that
it will help us in adding more RAM in to the server.


Thanks for your thoughts on this.

Anurag

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