3 Replies Latest reply: Mar 20, 2013 1:08 AM by moreajays RSS

    11.2.0.3 memory utilization

    Chewy
      Hi,
      We have a 11.2.0.3 database running on hp-ux.

      I have only allocated 2048MB (memory_taget) to Oracle.
      However from kmeninfo (summing up all the oracle processes), oracle is using about 5GB +.
      Each process is using between 12MB to 32 MB memory, as listed in kmeminfo. (is it part of SGA or PGA?)

      PGA is not using that much also.
      SQL> show parameter memory_target;

      NAME TYPE VALUE
      ------------------------------------ ----------- -------
      memory_target big integer 2048 M


      SQL> select n.name, sum(value)/1024/1024 as Mbytes from v$sesstat s, v$statname n
      2 where
      3 n.STATISTIC# = s.STATISTIC# and
      4 n.name like '%pga%'
      5 group by n.name;

      NAME MBYTES
      ---------------------------------------------------------------- ----------
      session pga memory max 671.01059
      session pga memory 451.600494

      Kindly share if u have idea on this or experience this before.

      thanks
        • 1. Re: 11.2.0.3 memory utilization
          moreajays
          Hi Chewy,

          What is the shared memory allocated at os ?

          kctune -v -q shmmax

          Thanks,
          Ajay More
          http://www.moreajays.com
          • 2. Re: 11.2.0.3 memory utilization
            Chewy
            Hi,

            Tunable shmmax
            Description Maximum size of a shared memory segment (bytes)
            Module vm_asi
            Current Value 4398046511104
            Value at Next Boot 4398046511104
            Value at Last Boot 4398046511104
            Default Value 1073741824
            Constraints shmmax >= 2048
            shmmax <= 4398046511104
            Can Change Immediately or at Next Boot


            thanks
            • 3. Re: 11.2.0.3 memory utilization
              moreajays
              Chewy,

              If you have calculated Total memory based on RES/SHR component of top then higher limit per process can be as high you have allocated share memory at OS level
              If calculated based on Virtual then it has upper limit of your SGA.

              Oracle server processes can eats up as much as memory available in system until they are restricted at OS level per osuser which leads to more paging

              Thanks,
              Ajay More
              http://www.moreajays.com