Reporting Tables (Denormalize tables)

  • While you can have rows of a size larger than 8060 bytes in SQL 2005, they should still be avoided.

    The page size hasn't changed and the largets row that can fit onto a page is around 8060 bytes. If portions of a row exceed that they are pushed off page, much like TEXT and IMAGE datatypes were in SQL 2000 (and the max data types are in SQL 2005)

    This can result in increased IO and decreased performance when querying tables with large row sizes, as the LOB pointer pas to be followed to find the 'remainder' of the row, and extra pages have to be read.

    In SQL 2000, inserting a row with a size > 8060 bytes throws an error (unless you are using TEXT, NTEXT or IMAGE data types)

    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
  • Thank you for the answer.

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