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IBM Cognos 8 Platform => COGNOS 8 => Report Studio => Topic started by: rhythmz on 03 Sep 2009 10:50:07 AM

Title: A few questions regarding Report Studio???
Post by: rhythmz on 03 Sep 2009 10:50:07 AM
When I create a calculation within Report Studio, it there any benefit to:

pulling the components of a calculation and then building the calculation on those "local" components

OR

build the calculation using the pkg. item (i.e. [FRUITS].[apples] vs. [apples])??

Will either produce different results or affect performance?

ALSO...

What is the difference between a Query Calculation vs. Data Item?

Will either produce different results or affect performance?

Thanks!
Title: Re: A few questions regarding Report Studio???
Post by: david.stachon on 03 Sep 2009 01:27:11 PM
there are some nice advantages to items locally...

1) It tends to make calculations more readable,

2) You can do some nifty things with "macros".

For example, this doesn't work:

#sb ( 'FRUITS].[apples' )#

but this does:

(provided [apples] is in the query)

#sb ( 'apples' )#

I haven't noticed any performance difference either way, but it's always worth testing.

(note: although the example is trivial, this type of thing can be quite useful ....for example, a prompt that asks you for a particular column to return. using a macro is WAY better than a case statement in this scenario)

"What is the difference between a Query Calculation vs. Data Item?"

....none. a "Query Calculation" is available on the Report Page view, and "Data Items" in the query view.  ...they both result in the same thing. No performance difference whatsoever.



Title: Re: A few questions regarding Report Studio???
Post by: rhythmz on 03 Sep 2009 05:37:14 PM
Thank you for finally putting that to rest for us. I needed someone to make sense of it all.