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How the transactions will move to mdf from ldf?

  • April 14, 2011 at 9:04 am

    #237614

    Hi All,

    Can you please tell me how transactions will commit to mdf from transaction file ? and who will take care of this process?

    Thank You.

    Regards,
    Raghavender Chavva

  • April 14, 2011 at 9:26 am

    #1311692

    I assume by transaction file you mean the log file

    Check points are issued by the system. If you want to know more look up checkpoint and lazywriter. It is an automatic process.

    If everything seems to be going well, you have obviously overlooked something.

    Ron

    Please help us, help you -before posting a question please read[/url]
    Before posting a performance problem please read[/url]

  • April 14, 2011 at 11:04 am

    #1311740

    Yes, transaction file means transaction log file.

    Is WLF will come into the picture here ?

    Thank You.

    Regards,
    Raghavender Chavva

  • April 14, 2011 at 11:06 am

    #1311741

    Yes, transaction file means transaction log file.

    Is WLF will come into the picture here ?

    Thank You.

    Regards,
    Raghavender Chavva

  • April 14, 2011 at 11:09 am

    #1311742

    Yes, transaction file means transaction log file.

    Is WLF will come into the picture here ?

    What do you mean by WLF?

    If everything seems to be going well, you have obviously overlooked something.

    Ron

    Please help us, help you -before posting a question please read[/url]
    Before posting a performance problem please read[/url]

  • April 14, 2011 at 2:00 pm

    #1311850

    They don't move. Data does not move from the log to the data file.

    When a transaction occurs the data page is changed in memory and the log record is written to the log buffer. When the transaction commits, the log buffer is written to disk, to the transaction log (ldf). At some point after that the changed data page is written to the data file.

    That's a massive simplification, but it's good enough.

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass

  • April 18, 2011 at 2:58 am

    #1312639

    Hi All,

    when we do any operation or transaction all are logged into log buffer.when you run the checkpoint save the all data to main database.

    Regards
    venkat

  • April 18, 2011 at 5:25 am

    #1312685

    kvr1985 (4/18/2011)

    Hi All,

    when we do any operation or transaction all are logged into log buffer.when you run the checkpoint save the all data to main database.

    Couldn't understand the question?

    Muthukkumaran Kaliyamoorthy
    https://www.sqlserverblogforum.com/

  • April 25, 2011 at 3:59 am

    #1315345

    could you please explain that question.

    Regards
    venkat

  • April 25, 2011 at 4:10 am

    #1315350

    If you can clarify what you're asking, maybe. As it is, I don't understand the question.

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass

  • July 24, 2011 at 11:13 pm

    #1357608

    Hi Raghavender.

    This link will help you :

    You can get some info about Checkpoint , Lazywriter and Write Ahead Logging as well.

    Regards,
    Saravanan

  • July 24, 2011 at 11:58 pm

    #1357616

    GilaMonster (4/14/2011)

    They don't move. Data does not move from the log to the data file.

    When a transaction occurs the data page is changed in memory and the log record is written to the log buffer. When the transaction commits, the log buffer is written to disk, to the transaction log (ldf). At some point after that the changed data page is written to the data file.

    That's a massive simplification, but it's good enough.

    This is a awesome simplication. We could as well save this one for our reference :).

    M&M

  • July 26, 2011 at 12:00 am

    #1358246

    Thanks Gila,

    Simple enough to understand big process within SQL engine.

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