2 Replies Latest reply: Sep 25, 2017 11:24 AM by Amit Saini RSS

    Performance Issue with Left Join

    Amit Saini

      Hi Folks,

       

      I'm having 45 tables in SQL named as Tab1,Tab2.....Tab45 ,which I have stored as QVD's.Each table is having column as below:

       

      Like Tab1 is having 928 Columns , Tab2 =776  and so on.  In all the tables I'm having ID as key to connect all 45 tables.

       

      To connect the data , I have used left join like below, but performance is too slow.

       

      Fact:

      Load ID,

      XYZ

      ---

      From

      Tab1

       

      Left Join (Fact)

       

      Load ID,

      ABC.

      From

      Tab2

       

      Left Join (Fact)

       

      Load ID,

      PQR

      From

      Tab3

       

      --

      --

       

      --

      Left Join (Fact)

       

      Load ID,

      HGT

      From

      Tab45

       

      Row size is fine ,but I'm having so many Fields and all of them are important.

       

      Can anyone suggest other ways of handling such data???

      Thanks,

      Amit