topic Re: Performance question in QlikView

Performance question

Mon, 26 Jan 2026 18:19:17 GMT

Hello,

I'm just now wondering whether there is a performance penaly when using a text field instead of number one in expressions.

Let's say I have the following fields among others:

- session_id which is a distinct number for each session with the following Qlikview tags ($key, $numeric, $integer) (e.g. 10340)

- id which is a distinct string for each session with the following Qlikview tags ($ascii, $text) (e.g. 0a0a24def1c42c6b14195ebdf9b3)

And then most of my charts are using expressions like:

COUNT(DISTINCT session_id)

My idea is just use id because it is already unique so will allow me remove session_id which I've to generate using sequences.

Then the big question would be:

- Will Qlikview perform as good as it is now? or by using text fields this would make qlikview performing really bad?

I will do a test but before I'd like to gather some of your experience on this.

Thanks in advance,

Ferran.

Re: Performance question

Colin-Albert — Fri, 24 Jan 2014 11:47:22 GMT

Henric's Blog has the answers

http://community.qlik.com/blogs/qlikviewdesignblog/2013/10/22/a-myth-about-countdistinct#comment-10487

Re: Performance question

Fri, 24 Jan 2014 13:29:47 GMT

I set your answer as helpful but I haven't been able to find an answer for my question in that thread.

Thanks,

Ferran

Re: Performance question

Colin-Albert — Fri, 24 Jan 2014 13:56:06 GMT

The comments against Henric's Blog have some options that are relevant to count performance and your specific question.

The factor that seems to influence the count performance is whether the field you are counting is in the fact table or if you are counting a field in an associated table especially if there are multiple hops across other tables to the field.