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Message Posted: Tue, 13 May 2003 @ 15:26:24 GMT


     
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Subj:   Re: Join Index question -- Partially Covered Case
 
From:   Claybourne Barrineau

I think Carrie is right, you can only use RowID Partially covering JIs with a single table JI.

With the number of columns you're dealing with, even V2R5 won't help (I think the new limit will 64 columns per table.)

What you can do (and this will cost a great deal of disk space and CPU) is generate a Unique value column (surrogate ID) of your UPI using the CSUM function (1,UPI Column Names), and divide you table into mulitple pieces (each with the new surrogate ID plus 15 columns.) Then, via your JI definition, you would need to join all of these tables together bases on the Surrogate ID (use Left outer joins so that all tables don't have to be joined together in every incoming SQL statement in order for the JI to be used, just the tables needed....Note, your cannot use Left Outer Joins with AJIs)

Soft RI for JIs will greatly help with the scenario described above, but soft RI for JIs isn't slated until V2R5.1 (hopefully, I think.)


Hope this helps,

Clay



     
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