topic Re: Performance comparison between aggr() and Intervalmatch in QlikView

Performance comparison between aggr() and Intervalmatch

datanibbler — Fri, 18 Oct 2013 17:02:01 GMT

Hi,

I just read in my book "QlikView 11 for Developers", the chapter about using the "Class" function,

in particular about building that fct. into a nested aggregation with AGGR() and using that as dimension.

I have a QlikView app where the outcome is a diagram that looks essentially like the one used as an example

in the book:

=> I calculate how many remaining holidays (not yet taken and not planned) every employee has, I group

them into categories ("-1 to 0", "1 to 10" etc.).

<=> Only in that app I use a different approach:

- I calculate that "holiday remaining" in a rather complex way from three tables

- Then I use the Intervalmatch fct. to group that into categories which I specify in an Inline table.

I think I remember once reading that calculated dimensions using aggr() are quite

resource-heavy, but I'd still like to be sure here:

=> Is the approach using IntervalMatch the faster/ less resource-heavy way or is it the one using aggr()?

Thanks a lot!

Best regards,

DataNibbler

Re: Performance comparison between aggr() and Intervalmatch

Clever_Anjos — Fri, 18 Oct 2013 17:04:46 GMT

It depends, there are other variables (quantity of rows, complexity of your AGGR expression)

Usually script level calculations use resources only one time (at reload) and AGGR will recalculate every selection was made.

Re: Performance comparison between aggr() and Intervalmatch

datanibbler — Mon, 21 Oct 2013 07:15:02 GMT

Hi Anjos,

that was all the answer I was looking for.

Of course it is more complicated than that, there are always several factors involved. But I can understand that a calculation made only once is faster than one made every time the user selects something.

Thanks a lot!

Best regards,

DataNibbler