Additive, Semi-Additive and Non-Additive

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Additive, Semi-Additive and Non-Additive

sabarichandru

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July 7, 2010 at 5:52 am

#147917

Hi ,
I like to know what is Additive Fact , Semi Additive Fact and Non-Additive fact. and if anybody explains me with examples will be great to me .
Thanks in Advance!
Sabarinathan.C

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Raunak Jhawar SSCoach Points: 15701 More actions · Answer 1

Hi Sabarinathan,

Let us begin with the definition of each which will be followed by examples:

1. Additive measures: These are those specific class of fact measures which can be aggreagated across all dimension and their hieracchy

2. Semi-Additive measures: These are those specific class of fact measures which can be aggreagated across all dimension and their hieracchy except the time dimension

3. Non-additive measures: These are those specific class of fact measures which cannot be aggreagated across all/any dimension and their hieracchy

For example:

A) We have sales figures...one may tend to add sales across all quareters to avail the yearly sales..hence this is an example of Additive measure

B) We have stock levels say 1000(qty of Item A) on Monday...I sell 200(qty of Item A) on Tuesday I further sell 300(qty of Item A) on Wednesday...going by basic math On Thursday I should be left with 500(qty of Item A, assuming no inventory has flown in) to obtain current stock level I cannot aggregate the Stock sales across time dimension hierarchy...If done I will have inappropriate outcomes

C) Aggregation of percentage or dates is an Ideal example of non-additive measures.

Hope this helps.

Raunak J

sabarichandru SSCommitted Points: 1704 More actions · Answer 2

Hi Raunak,

First come first i like to thanks for ur quick response . your explaination is clear n crispy.

but i like to know more about semi - additive Non-Additive fact. because in what situation you will prefer semi and non additive. how u will handle those situation .

Eg: suppose percentage cannot be roll up in non-additive even ratio values in those situation how u will handle.

Thanks and Regards,

Sabarinathan.C

RonKyle SSC-Dedicated Points: 31556 More actions · Answer 3

The issue is when you would prefer one or the other, just a recognition of what applies and what you can do to help your users to recognize limitations. My additive members have short names, Completed, Completed %. My semi or non additives might have a name such as Client % Work orders, to signal that the value functions only against the Client dimension.

Duncan Sutcliffe Old Hand Points: 312 More actions · Answer 4

A good example of a non aggregatable measure might be 'Price' on a sales record. It would make no sense to ever add these up or do any other kind of aggregation, therefore you would set their aggregation type to 'None'.

To handle percentages such as profit margin %, you don't store the percentage on the record as an aggregateable measure but you create a calculated measure which does the right maths. Because calculated measures are calculated at query time for the level currently being displayed, they will always be correct.

Good luck,

Duncan