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IBM Cognos 10 Platform => Cognos 10 BI => Report Studio => Topic started by: Todd129 on 06 Feb 2013 02:41:13 PM

Title: Query Calculation vs Data Item?
Post by: Todd129 on 06 Feb 2013 02:41:13 PM
Hi there --

This may be a dumb question, but can one of the gurus please clarify for me when a query calculation should be used instead of a data item?

Many thanks!

Todd
Title: Re: Query Calculation vs Data Item?
Post by: RKMI on 06 Feb 2013 06:09:27 PM
"What is the difference between a Query Calculation vs. Data Item in Report Studio?"

....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.

In Framework Manager creating a data item can be reused across reports. please see this link, http://www.cognoise.com/index.php/topic,14236.msg45087.html#msg45087

Thanks,
RK
Title: Re: Query Calculation vs Data Item?
Post by: Todd129 on 06 Feb 2013 06:26:51 PM
Excellent -- many thanks
Title: Re: Query Calculation vs Data Item?
Post by: _jl_ on 27 Jun 2013 03:14:09 AM
Quote from: RKMI on 06 Feb 2013 06:09:27 PM
"What is the difference between a Query Calculation vs. Data Item in Report Studio?"

....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.

In Framework Manager creating a data item can be reused across reports. please see this link, http://www.cognoise.com/index.php/topic,14236.msg45087.html#msg45087

Thanks,
RK

Noticed this topic and have to bump this up. :) Just noticed that in addition to 'Data Item', in the query view there is also 'Query Calculation', isn't there? Don't these two have any difference? If not any, I wonder why is there both two?

BR,
jl
Title: Re: Query Calculation vs Data Item?
Post by: _jl_ on 04 Jul 2013 12:13:10 AM
Was that too dumb question or no one really knows?  :o
Title: Re: Query Calculation vs Data Item?
Post by: CognosPaul on 04 Jul 2013 01:26:05 AM
Dragging in a query calculation will allow you to create what is called an extended data item. These can be calculated members, calculated measures, or set expressions. In the layout, you can use the gui to work with these items (create a set expression, drag it into a crosstab, and right click on it to see what I mean.

Data items allow you to define your expression manually. You cannot use the gui wizards.

Personally I prefer data items. But there may be some circumstances where extended data items are prefered.
Title: Re: Query Calculation vs Data Item?
Post by: inu on 02 Aug 2014 02:04:40 PM
Quote from: CognosPaul on 04 Jul 2013 01:26:05 AM
Dragging in a query calculation will allow you to create what is called an extended data item. These can be calculated members, calculated measures, or set expressions. In the layout, you can use the gui to work with these items (create a set expression, drag it into a crosstab, and right click on it to see what I mean.

Data items allow you to define your expression manually. You cannot use the gui wizards.

Personally I prefer data items. But there may be some circumstances where extended data items are prefered.

Hi Paul,
What is the meaning of GUI wizard, if we drag a data item, then definitely a dialogue box pops up, is that a GUI wizard???
Please mention the more specific view.

Thanks
Inam
Title: Re: Query Calculation vs Data Item?
Post by: sunny bachan prasad on 02 Aug 2014 10:38:17 PM
Hi Todd,

when we have to show any calculation(EG.%,Variance,sub) in the report as one of the column then in spite of taking the data item we used to take Quary calculation even u can do it in the data item but while doing the automatic summary(if you have a requirement) it make differences.If u have access to cognos software then u can do this exp and see the differences.