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IBM Cognos 10 Platform => Cognos 10 BI => Framework Manager => Topic started by: raj_aries81 on 06 Nov 2014 01:23:12 PM

Title: Reporting Traps - FAN Trap
Post by: raj_aries81 on 06 Nov 2014 01:23:12 PM
Hi Gurus,

I was looking at some use cases around reporting traps.

I tried to replicate a scenario for FAN Trap with two tables something similar to Table A -< Table B based on Dave's blog http://www.dagira.com/2008/03/03/do-i-have-a-fan-trap/

For Eg: I Created two tables OrderHeader & OrderDetails with the below columns

OrderHeader - [order_id],[order_date] and [order_budget]

OrderDetails -   [order_line_id],[order_id],[item_id] and [order_qty]

Now, after I join OrderHeader & OrderDetails and select the measures from both the tables, the measure in the OrderHeader will obviously be inflated and will multiplied by the number of line items in the OrderDetails table.

Here are my questions around this  -

1) How can this be called a FAN Trap, this can be easily handled by changing the aggregate properties for the Measure coming from OrderHeader table to 'None' to avoid any aggregation being applied.

2)Changing the cardinality from A-<B to A-B would also doesn't make any difference. Since both would generate the same query in this scenario

3)Can we use determinants to handle this scenario.

Regards
Raj

Title: Re: Reporting Traps - FAN Trap
Post by: raj_aries81 on 07 Nov 2014 07:49:10 AM
Can anyone help me out by clarifying my confusion around it

Raj