dirty buffers
DBAsupport.com Forums - Powered by vBulletin
Results 1 to 4 of 4

Thread: dirty buffers

  1. #1
    Join Date
    Jun 2000
    Location
    Madrid, Spain
    Posts
    7,447
    Hi

    Does anyone know if datafile can contain data that are not validated but are written to the datafile by DBWR because the data buffer is full?


    Cheers

  2. #2
    Join Date
    Aug 2000
    Posts
    236
    Pando,

    Of course it can. By validate, I take it that you mean "comitted".

    Ireespective of data bring comitted or not (the dirty buffer write que) DBWR writes them back to disk. If they are rolled back, data is reconstructed using the SCN and the RBS.

    The Oracle fast commit mechanism commits the data only in the redolog buffer and files.

    Nizar.

  3. #3
    Join Date
    Jun 2000
    Location
    Madrid, Spain
    Posts
    7,447
    well I am just puzzled that in an instance failure the redo logs protects changes made to database buffers in memory that have not been written to the datafiles, what happen to those data which are not validated but written to the datafile in an instance failure? Since there arent any rollback or commit.

  4. #4
    Join Date
    Jun 2000
    Location
    Madrid, Spain
    Posts
    7,447
    aps got it they will be rolled back since last checkpoint

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Click Here to Expand Forum to Full Width