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IBM Cognos 10 Platform => Cognos 10 BI => Framework Manager => Topic started by: pramodb on 14 Nov 2013 09:46:57 PM

Title: How to handle Cardinality in Cognos 7 migration to Cognos 10
Post by: pramodb on 14 Nov 2013 09:46:57 PM
Hi

In Cognos 7, joins used to be simpler as Left/Right/Full Outer Join or Inner Join.
There was no cardinality to deal with. Now in migration of Cognos 7 catalog to Cognos 10 framework model, how to add these cardinalities.


Thanks
Title: Re: How to handle Cardinality in Cognos 7 migration to Cognos 10
Post by: MFGF on 15 Nov 2013 05:20:46 AM
Just edit each relationship and choose the relevant cardinality at each end.

MF.
Title: Re: How to handle Cardinality in Cognos 7 migration to Cognos 10
Post by: pramodb on 15 Nov 2013 10:37:14 AM
i meant how to decide the cardinality like for  Outer Join, what should it be 0..1/0..n? How to decide this?
Title: Re: How to handle Cardinality in Cognos 7 migration to Cognos 10
Post by: Lynn on 15 Nov 2013 01:20:36 PM
Is formal training an option for you to consider? The leap from 7 to 10 is rather a large one.

Reviewing the user guide might also be helpful. Chapters 5 and 9 are particularly relevant to your question. I suppose a simple answer to your question is that you should have a star schema without outer joins and that your facts should be on the n side of all relationships.

Since your model is the basis for all reporting it is important that you understand more than just simple answers like that, so some amount of time spend on education won't be wasted effort.
Title: Re: How to handle Cardinality in Cognos 7 migration to Cognos 10
Post by: pramodb on 16 Nov 2013 11:11:59 AM
i am talking about the scenario when same table is being used as dimension or fact then for an outer join what should be the cardinality,0..n or 0..1 for this table?

I have Cognos 7/8/10 experience, just not sure how this works in lack of detailed knowledge about the tables in question.

And how wrong can a (1..1 --- 0..1) be when (1..1 --- 0..n) should be applied?
Title: Re: How to handle Cardinality in Cognos 7 migration to Cognos 10
Post by: cognostechie on 16 Nov 2013 02:00:44 PM
I concur with everything Lynn said and with a proper star schema , you would never treat the same table as a Dimension and Fact. One table would be treated either as a Dimension or as a Fact, not both. The training would have answered your other question about how wrong can a (1..1 --- 0..1) be when (1..1 --- 0..n) should be applied?

http://www.cognoise.com/index.php/topic,23155.0.html