very Frequent redo switch
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Thread: very Frequent redo switch

  1. #1
    Join Date
    May 2002
    Posts
    163

    very Frequent redo switch

    Hello Everybody,

    see the time below, for each redo switch from server

    MINUTES
    ----------
    13.9
    9.95
    5.93
    5.7
    6.17
    6.17
    5.87
    6.17
    6.93
    7.05
    6.35
    6.83

    The size of each archive is also 1G.

    1048574976 Nov 15 07:12 _8431.arc
    1048574976 Nov 15 07:29 _8432.arc
    1048568832 Nov 15 07:47 _8433.arc
    1048574976 Nov 15 08:07 _8434.arc
    1048572928 Nov 15 08:23 _8435.arc
    1048574976 Nov 15 08:39 _8436.arc
    1048574976 Nov 15 08:56 _8437.arc
    1048572928 Nov 15 09:14 _8438.arc

    My redo log size is 1G. The log block size is 1024 on HP. In my DB log_checkpoint_timeout is set to 86400, but Oracle recommends to set log_checkpont_interval which should be calculated as log block size.

    1) I would like to set my checkpoint_interval = (1G*1024*1024*1024)/1024 is that fine?
    2) I am thinking to increase the size of redo log size to 2G.

    Please suggest me what should I do?


    Regards
    Nwcomer
    Student

  2. #2
    Join Date
    Nov 2000
    Location
    greenwich.ct.us
    Posts
    9,092
    I'm not sure what "MINUTES" is, but your archive activity doesn't look bad to me. Do you get any "Checkpoint not complete" messages in your alert.log?
    Jeff Hunter
    marist89@yahoo.com
    http://marist89.blogspot.com/
    Get Firefox!
    "I pledge to stop eating sharks fin soup and will not do so under any circumstances."

  3. #3
    Join Date
    May 2002
    Posts
    163
    Minutes = each redo switch time difference.Not always, but very often the time diff is only 3 -4 minutes.

    No I did not get any "checkpoint not complete" error.

    But I am thinking about Load of redo switch. Frequent redo switch has lot of overheads and performance can degrade since each datafile will be frozen during each redo switch.

    What do you suggest?


    Regards
    Nwcomer
    Student

  4. #4
    Join Date
    Sep 2002
    Location
    England
    Posts
    7,333
    tune your code to produce less redo - simple

  5. #5
    Join Date
    May 2002
    Posts
    163
    The application has to do lot of updates.
    Nwcomer
    Student

  6. #6
    Join Date
    Nov 2000
    Location
    greenwich.ct.us
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    9,092
    Originally posted by newcomer
    The application has to do lot of updates.
    Then the database will have lots of redo.
    Jeff Hunter
    marist89@yahoo.com
    http://marist89.blogspot.com/
    Get Firefox!
    "I pledge to stop eating sharks fin soup and will not do so under any circumstances."

  7. #7
    Join Date
    Oct 2002
    Posts
    807
    If it's a warehouse or something, you might want to look into NOLOGGING operations.

  8. #8
    Join Date
    Jan 2001
    Posts
    3,131
    That does not look bad to me.
    Is this consistant or were they running a large job?
    Has DB performance suffered recently?
    I have seen them less than 30 seconds apart, but it does not last for too long so no cause for alarm.
    I remember when this place was cool.

  9. #9
    Join Date
    Aug 2002
    Location
    Colorado Springs
    Posts
    5,253
    Originally posted by Axr2
    If it's a warehouse or something, you might want to look into NOLOGGING operations.
    That's a pretty big decision to make -- wouldn't help with updates of course.
    David Aldridge,
    "The Oracle Sponge"

    Senior Manager, Business Intelligence Development
    XM Satellite Radio
    Washington, DC

    Oracle ACE

  10. #10
    Join Date
    Oct 2002
    Posts
    807
    Originally posted by slimdave
    That's a pretty big decision to make -- wouldn't help with updates of course.
    I was just providing him/her food for thought, that's all.

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