none
Torn page detection enabled on 2008 sp3 RRS feed

  • Question

  • Hi We have SQL Server database 2008 SP3 and enabled Torn page detection. But question is change to checksum from "torn page detection" is recommended practise for this version. But new versions are by default  checksum enabled. Please note "torn page detection" enabled databases backup with "checksum" option . I understand If we enabled "checksum" then does not it cover "torn page detection" purpose.

    Any expert advise is highly appreciated


     

    • Edited by ashwan Thursday, September 12, 2019 8:03 PM
    Thursday, September 12, 2019 7:52 PM

All replies

  • Hello,

    Actually checksum is a kind a "evolution" of torn page detection. They have the same purpose: check the data page consistency; where torn page checks the page using partial data of the data pages and checksum uses the full page. It's known that checksum has a bit more overhead than torn page detection. Until i know you can use checksum during backups when using the page verify "checksum" as well.

    Regards,
    Rafael


    Thursday, September 12, 2019 8:33 PM
  • Hi ashwan,

    Please refer to below links to get more information.
    Whats best: Torn Page Detection or Checksum
    Checksum vs Torn Page Detection - performance

    Best regards,
    Cathy 

    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to  MSDN Support, feel free to contact MSDNFSF@microsoft.com

    Friday, September 13, 2019 9:01 AM
  • You should have Checksum enabled it is way better than tor page detection. There is no harm in doing that please go ahead and change it. Please note when you change there would be no real affect the real affect would only come into picture or the checksum would actually be implemented when page is read into memory changed/updated and then written back to the disk.

    Cheers,

    Shashank

    Please mark this reply as answer if it solved your issue or vote as helpful if it helped so that other forum members can benefit from it

    My TechNet Wiki Articles

    MVP

    Friday, September 13, 2019 10:24 AM
    Moderator
  • Hi Shanky and Cathy Many thanks for the info. However I am having other Q then. 

    . I understand adding new data will work fine. But say if  enabled to "CHECKSUM" from Torn Page Detection at the middle, when read from the disk  to compare page header information , then header info is not available  which written to while a back.(say enabled 14/09/2019 6am. I am referring prior to that). Then how SQL Server would know this after enabled "Checksum" at the middle. 

    many thanks

     
    • Edited by ashwan Friday, September 13, 2019 8:55 PM
    Friday, September 13, 2019 8:32 PM
  • Hi Shanky and Cathy Many thanks for the info. However I am having other Q then. 

    . I understand adding new data will work fine. But say if  enabled to "CHECKSUM" from Torn Page Detection at the middle, when read from the disk  to compare page header information , then header info is not available  which written to while a back.(say enabled 14/09/2019 6am. I am referring prior to that). Then how SQL Server would know this after enabled "Checksum" at the middle. 

    many thanks

     
    When the page is read checksum would not be applied only when it is written back to disk checksum would be used. The information must be stored somewhere on header that checksum is enabled. This is internal process and I do not have much info about how this is exactly done

    Cheers,

    Shashank

    Please mark this reply as answer if it solved your issue or vote as helpful if it helped so that other forum members can benefit from it

    My TechNet Wiki Articles

    MVP

    Monday, September 16, 2019 6:49 AM
    Moderator