SQL Server Performance

Question about Using PreCalc'd hash for joins

Discussion in 'SQL Server 2008 General DBA Questions' started by MdTravler, Jan 10, 2011.

  1. MdTravler New Member

    I have a large table around 100 million rows.. I want to join a particular column varchar column in this table to another table of a few million emails to check for the existence in one table against another table. Would there be an efficiency gained by computing a checksum for the varchar column - indexing and using that to join?
  2. satya Moderator

    Welcome to the forums.
    How frequently you are going to execute this query?
    For SELECT query performance indexes would always help, but given the data type of the columns you may be wasting space and it may lead to table scan which may hamper the performance.

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