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IBM Cognos 10 Platform => Cognos 10 BI => Framework Manager => Topic started by: inu on 11 Apr 2014 04:37:21 AM

Title: how to identify the degenerated dimension
Post by: inu on 11 Apr 2014 04:37:21 AM
Hi
As i know the definition theoritically of degenrated dimension that "it is a dimension which is derived from the fact table and doesnot have its own corresponding dimension table" Is it correct dimension.

Second thing is that , how can i know that the particular dimension is degenerated dimesion. Please guys give explanation with example.

I will be thankful to all of you community.

Regards
Inam
Title: Re: how to identify the degenerated dimension
Post by: MFGF on 11 Apr 2014 05:08:24 AM
Hi,

If you look at a fact table, it will usually contain items of two types:

Measure values
Keys that link the fact table to a dimension table.

If your fact table contains a value that isn't a measure, and isn't a key that links to a dimension table, this value is considered as a degenerate dimension. You will often find that Cognos doesn't handle degenerate dimensions well when constructing queries, so a common technique is to fake a dimension for it by creating a new query subject containing just this item and adding a relationship that links it 1..1 <--> 1..n to the item in the Fact (so it behaves like a real dimension).

Regards,

MF.
Title: Re: how to identify the degenerated dimension
Post by: inu on 12 Apr 2014 05:59:10 AM
Hi MFGF
Thanks for your valuable response. I got your point a little bit that if a fact table doesnot have measure value or key then the value is considered as degenerated dimension.

Please give one example , because i m a beginner to cognos.

Regards
Inam