Author Topic: Outer joins in FW  (Read 3342 times)

Offline addicted2cognos

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Outer joins in FW
« on: 11 Jan 2008 01:57:02 pm »
Anybody faced problems using outer joins in fw(trying to implement a left outer join) with an inner join to another table
« Last Edit: 11 Jan 2008 03:03:38 pm by addicted2cognos »

Offline Arpit Agrawal

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Re: Outer joins in FW
« Reply #1 on: 14 Jun 2011 06:16:53 am »
What is the issue you are facing,In case you want to impliment a Left/Right Outer join,you can change the cardinality to 0 for the side which is deficit of the information.

Hope this helps,Let me know in case you still face any issue.

Regards,
Arpit
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Offline wyconian

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Re: Outer joins in FW
« Reply #2 on: 21 May 2012 10:45:08 am »
Hi

Arpit answers is really good for the question you asked.  But, outer joins are bad in terms of performance and can make it harder to write reports.

Is your model based on a  datawarehouse?  If it is and you're using Data Manager as the ETL engine you can add something called a static member to the dimension builds.  This is like a default value for the 'Unknown' or 'missing' record in the dimension.  When you then come to do the surrogate key substitution on the fact table you can decide to use the static member if the real record cab't be found or is missing.  In this way you can completely remove the need for outer joins in the model, improving performance and making the reports easier to write :)

 


       
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