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High Buffer Pool read time? - IBM DB2

DB2 UDB v7.2 on AIX4.3.3. The following snapshot is taken for an application that is inserting/updating very slowly, i.e. ca. 1 row every second (there is no lock contention, but an update trigger is called for each row). Statistics are up-to-date. Can anyone point me in the right direction to attempt to speed this up? Thanks very much. Buffer pool data logical reads = 163688 Buffer pool data physical reads = 61634 Buffer pool data writes = 9 Buffer pool index logical reads = 23633 Buffer pool index physical reads = 2289 Buffer pool index writes = 10 Total buffer ...

  1. #1

    Default High Buffer Pool read time?

    DB2 UDB v7.2 on AIX4.3.3.

    The following snapshot is taken for an application that is
    inserting/updating very slowly, i.e. ca. 1 row every second (there is
    no lock contention, but an update trigger is called for each row).
    Statistics are up-to-date. Can anyone point me in the right direction
    to attempt to speed this up? Thanks very much.

    Buffer pool data logical reads = 163688
    Buffer pool data physical reads = 61634
    Buffer pool data writes = 9
    Buffer pool index logical reads = 23633
    Buffer pool index physical reads = 2289
    Buffer pool index writes = 10
    Total buffer pool read time (ms) = 487004
    Total buffer pool write time (ms) = 553
    Time waited for prefetch (ms) = 11
    Direct reads = 0
    Direct writes = 0
    Bruce Guest

  2. #2

    Default Re: High Buffer Pool read time?

    Hey Bruce,

    You did not specify a page size, but if this is a 4KB pagesize then it looks
    to me that your read time might be slow.
    You might wanna have a look at the performance for the disks the tablespace
    is on.

    Also, what exactly is the trigger doing? How fast does it go without the
    trigger?

    "Bruce Pullen" <com> wrote in message
    news:google.com... 


    Erik Guest

  3. #3

    Default Re: High Buffer Pool read time?

    "Erik Hendrix" <com> wrote in message news:<teranews.com>... [/ref]


    Does the trigger fire after an update or after an insert? What is the
    access path of the update trigger, did you explain it? Did you also
    explain the orignial insert and/or update? Does it run faster if the
    workload is all inserts or all updates? Take a snapshot for tables
    and tablespaces and see which tables are being most frequently read
    and which tablespaces are being accessed.
    Leo Guest

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