calculated dimension

[Anonymous]

what is calculated dimension?please explain with some example

[#2]

Hi,

Please follow this link.

Extracting Dimension / Field Name from Calculated Dimension in QlikView

Thanks

Stefan

[tresesco]

In a chart, you can take a field as dimension, similarly, you are allowed to write your expression to get your dimension values. While you are writing expression for defining dimension, that is called a calculated dimension.

Example: Field1 (A,B,C,D)

you might want to write an expression =If(Field1='A' or Field1='B', Field1)   // this will give you only two members in the dimension, and this is called a calculated dimension.

[m_woolf]

If my data set has a PartDate field, I can enter:

=if(Today()-PartDate<=14,'New','Old')

[Oleg_Troyansky]

Michael: which is excellent as an example, but not very good in real life applications.

We should always keep in mind that Calculated Dimensions are extremely heavy on a large scale, and in most cases should be avoided with static fields calculated in the load script.

The only well justified use of Calculated Dimensions is when we use aggregated functions to create histograms. Those dimensions can't be prepared in the load script and therefore have to be defined as calculated.

We discuss those issues at length within the Masters Summit for QlikView, where I teach both Advanced Aggregation and Performance Tuning, and we talk about calculated dimensions in both of those sessions.

cheers,

Oleg Troyansky