Thumbrule to size SGA
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Thread: Thumbrule to size SGA

  1. #1
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    Unhappy Thumbrule to size SGA

    Hi frnds,
    Is there any standard policy/thumbrule to size the SGA. How do i size memory structures based on number of expected users? Will that be a right move?

    Thanks,
    Kam

  2. #2
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    Hi Friend,

    For me I allocate 5Mb-10Mb per user
    Behind The Success And Failure Of A Man Is A Woman

  3. #3
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    Unhappy

    Hi,
    How did you arrived that figure? What is the logic behind that?

    Thanks in advance

  4. #4
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    Well, from some statistics that an average process being invoked by
    users consume 5Mb memory, and i read somewhere that it can be 1/4 of the physical memory. Then adjust it accordingly as no. of users increases.
    Last edited by yxez; 09-19-2006 at 05:19 AM.
    Behind The Success And Failure Of A Man Is A Woman

  5. #5
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    Hi,
    U mean SGA to be set 1/4 of Physical mem? I suppose ideal shd be 65% of Physical mem. Could anyone validate this answer?

    Thanks.

  6. #6
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    I mean the total SGA
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  7. #7
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    Quote Originally Posted by Kamkan
    Hi,
    U mean SGA to be set 1/4 of Physical mem? I suppose ideal shd be 65% of Physical mem. Could anyone validate this answer?

    Thanks.

    I have a server with 48GB physical memory and 6 instances running, dont think the rule you have heard about can be used.

  8. #8
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    May I know what are the total SGAs you used Pando? If I have
    that BIG MEMORY, I think I will start my SGA with 4Gb as baseline then adjust/tune it as I go along. Its just really in my instinct
    Behind The Success And Failure Of A Man Is A Woman

  9. #9
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    Red face

    Hi,
    Yes Pando. I agree. Is there any ideal way to calculate the mem requirements?

    Can anyone help to come out with clear idea?

    Thanks,
    kam.
    Last edited by Kamkan; 09-19-2006 at 08:41 AM.

  10. #10
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    There is no perfect rule in allocating memory for SGA, PGA, etc; and it varies system to system.
    You need to monitor the processes, collect statistics over period of time, and adjust the memory requirements accordingly.

    Tamil

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