Custom Calculator can skip SetValue

One of the less familiar features of ClickAnalyze infrastructure is the handling of a permutation full of nulls.

To be more clear, let say that a report is made of Time and Geography dimensions, and then 2 custom calculators. Assume that for the permutation "July 19, 2009", "North-East", "Boston" both calculators get short list of assignments. Both calculator find that the total they need to calculate is 0 (zero). This can happen due to the fact that this is Sunday and the calculators are considering the engineers' calendars.

So, let say that both calculators will include code that skip the SetValue method, when the value is zero:

If Not (totalSeconds = 0) Then
    pCalculatorsRowItem.SetValue(0, totalSeconds)
End If

The ClickAnalyze infrastructure identifies this as permutation with no data, means that all calculators skip the SetValue. By default, each report includes advanced property "Include Permutation With No Data" set to False. This means that our permutation will not be written to the database. Changing the property to True will cause the permutation to be written with nulls. This of-course might result with many more records full of redundant data.