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  1. #1
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    Unanswered: memory used by database

    what database configuration parameters can I use to calculate total amount of memory used by the database?

    Thanks
    DB2 9.5/9.7 on Unix/AIX 6.1/Linux

  2. #2
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    db2mtrk is one tool. db2pd also has provides information on memory. Check with the Comand Reference manual to see which options to use with these tools to get the information that you need.
    M. A. Feldman
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows
    IBM Certified DBA on DB2 for z/OS and OS/390

  3. #3
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    Quote Originally Posted by Marcus_A
    db2mtrk is one tool. db2pd also has provides information on memory. Check with the Comand Reference manual to see which options to use with these tools to get the information that you need.
    those 2 commands give me a snapshot of what is being currently used now. may be I should rephrase my question - how much max memory would the database use based on db cfg parameters? what db cfg params can I add up to calculate it?

    Thanks
    DB2 9.5/9.7 on Unix/AIX 6.1/Linux

  4. #4
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    please check this article:
    The DB2 UDB memory model


    There is a formula you can use to estimate your db shared memory (ie. bufferpools, locklist, dbheap, etc...). This is what gets allocated when the db is started.

  5. #5
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    Quote Originally Posted by MarkhamDBA
    those 2 commands give me a snapshot of what is being currently used now. may be I should rephrase my question - how much max memory would the database use based on db cfg parameters? what db cfg params can I add up to calculate it?
    Thanks
    A lot of that depends on which version of DB2 you are using (whether you have Self Tunning Memory Manager in the version you are using), and whether you have each parameter set to automatic or not. With automatic memory you can actually specify a maximum value that will be used in total for all the various database shared memory components (controlled by the database_memory configuration parameter).

    I assume you know that in addition to database memory, there is memory at the instance level, including memory required for each connection to a database.
    M. A. Feldman
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows
    IBM Certified DBA on DB2 for z/OS and OS/390

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