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Message Posted: Fri, 31 Jan 2003 @ 12:23:31 GMT


     
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Subj:   Re: Query optimization: difference between inner join and derived table?
 
From:   Doorey, Andrew ST

Have you tried to run it using a where clause to join the tables instead of the inner join?

When we first set up Microstrategy we found this more efficient, especially if there are other elements in the where clause, as it then filters out only the rows from table2 it needs before joining the tables. This doesn't seem to make a difference since we upgraded to a more recent version though.

You can set the join type in the Microstrategy VLDB properties. Choose 'SQL89 Inner Join and SQL92 Outer Join and Cross Join'

Also, if table2 isn't a unique list of rid's then you should build a table or view that is a unique list, map that into Microstrategy and set it as the lookup table. Microstrategy assumes that all attributes have a lookup table with unique values.



     
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