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Thread: problems with db_writer_processes parameter

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  1. #1
    Join Date
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    problems with db_writer_processes parameter

    Hallo,

    my DB is running with two CPUs. For more efective writing data to RAID 5 discs I try to start 4 db_writer_processes. I can start 2 but not 4 of them. Is there any rule I do not now?

    Please help me! Christian

    Oracle9i Release 9.2.0.1.0 - Production
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    Last edited by ckiltz; 05-14-2004 at 05:55 AM.

  2. #2
    Join Date
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    over the hill and through the woods
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    Hallo aus Heidelberg!

    go check out this on meta link it should answer your problem
    Oracle it's not just a database it's a lifestyle!
    --------------
    BTW....You need to get a girlfriend who's last name isn't .jpg

  3. #3
    Join Date
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    Hallo aus Berlin ;-)

    I canĀ“t open this link. How can I get an Oracle Support contract or the artikel?

    Thank you for help!

    Christian

  4. #4
    Join Date
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    Re: problems with db_writer_processes parameter

    Originally posted by ckiltz
    Hallo,

    my DB is running with two CPUs. For more efective writing data to RAID 5 discs I try to start 4 db_writer_processes.
    raid 5 ?? immmm very bad for performance.
    Last month only I say BYEBYE to Raid 5.
    Now in 0,1.
    Sleeping well in night.
    consider changing 5.

  5. #5
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    in order to access metalink you have to have a CSI number. Whomever bought Oracle at your shop would have this information. Simply goto http://metalink.oracle.com and register an account there. It takes all of about 5 minutes to do.
    If you don't have a CSI number reply back here and I'll cut and paste the note.
    Oracle it's not just a database it's a lifestyle!
    --------------
    BTW....You need to get a girlfriend who's last name isn't .jpg

  6. #6
    Join Date
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    Location
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    Re: Re: problems with db_writer_processes parameter

    Originally posted by engiri
    raid 5 ?? immmm very bad for performance.
    Last month only I say BYEBYE to Raid 5.
    Now in 0,1.
    Sleeping well in night.
    consider changing 5.
    ... It was not my decision to take RAID 5. I red in "Oracle9i Performance Tuning" RAID 5 is slow in writing but fast in reading in combination with Oracle.

    Greetings from Christian

  7. #7
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    Apr 2003
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    not all the oracle files in 5.
    isn't it?

  8. #8
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    Sorry but I don't have a CSI number.

    I only have to eMail Oracle and get one?

    Christian

  9. #9
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    If your redologs are on RAID-5, moving them to RAID-1 or multiplexed non-RAID will probably help more than more db writers.

  10. #10
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    You can only have as many dbwrites as you have db_block_lru_latches. Check this parameter and increase through your init.ora if necessary. However, bumping your dbwrites past 2 on a 2 cpu box will make them compete with each other if you in fact dbwriter can't get enough CPU already AND your on non-async filesystems.
    Last edited by marist89; 05-14-2004 at 08:08 AM.
    Jeff Hunter

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