topic Re: Set Analysis vs Suppress Zero/Null in QlikView

Set Analysis vs Suppress Zero/Null

robinrouleur — Tue, 20 Jan 2015 23:27:47 GMT

Can anyone advise whether it is more efficient to use an aggregation with set analysis (eg: Sum({$<Field={'value'}>} Count) or one with no set analysis (eg: Sum(Count) and a combination of "Suppress When Value is Null" on the Dimensions tab and "Suppress Zero-Values" on the Presentation tab?

In my use case both achieve the same result. My thinking is that set analysis avoids doing unecessary aggregations that are then suppressed and so should be more efficient, but it depends on how smart QlikView is under the hood.

Thx

Robin

Re: Set Analysis vs Suppress Zero/Null

Gysbert_Wassenaar — Wed, 21 Jan 2015 11:37:04 GMT

Interesting question. I have no idea. Perhaps hic can tell us the answer.

Re: Set Analysis vs Suppress Zero/Null

hic — Wed, 21 Jan 2015 20:35:27 GMT

I haven't tested it, but I would guess that "Presentation -> Suppress Zero-values" is more efficient since it uses existing selection, whereas Set Analysis makes a new selection that needs to be evaluated.

The setting "Dimensions -> Suppress when value is NULL" only affects the dimension, and not the "Count" that you use in your aggregation.

HIC