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IBM Cognos 8 Platform => COGNOS 8 => Framework Manager => Topic started by: tupac_rd on 24 Aug 2010 01:44:30 PM

Title: join question
Post by: tupac_rd on 24 Aug 2010 01:44:30 PM
Hi,

I have 2 tables, member and member master, which are joined as

Member Master . pk = member. fk

Each of these 2 tables are joined to 5 other tables.

In FM, I am planning to merge member and member master, into a single query subject, and then join this to the 5 other tables. Is this the correct approach.

Now, when I join the merged query to the 5 other tables, should the join be based on the primary key of member master or member.

Thanks
2pac
By the how do I insert an image file.
Title: Re: join question
Post by: blom0344 on 25 Aug 2010 02:30:58 AM
It depends..

Merging objects that do not store facts is usually a good idea (called reducing snowflaking)

The join between the other 5 tables could either be pk_master or pk_member depending on the object you join with.

Merging objects makes the overall model more 'understandable' , it will not really changes which join are performed in the end (though the  SQL may differently structured)