topic Re: Performance Impact in QlikView

Performance Impact

Anonymous — Mon, 26 Jan 2026 18:19:17 GMT

Hi All,

Can anyone of you please tell me which one is better to use in Set Analysis Expressions -

Only()

Maxstring()

Concat()

Which one will have least impact on Performance.

Please assist on same.

Regards,

Re: Performance Impact

cesaraccardi — Thu, 21 May 2015 10:45:13 GMT

Hi,

Can you provide an example of whatyou would like to achieve?

Re: Performance Impact

manojkulkarni — Thu, 21 May 2015 10:47:21 GMT

use of above function dependent on your requirement and on what type field being used.

Re: Performance Impact

Anonymous — Thu, 21 May 2015 10:49:28 GMT

Suppose I have a requirement where I want to write condition like -

Maxstring({<field=P({<$(var1)>}field2),$(var2), field3=>}field4)

In this case, which expression will be having least impact on Performance, whether i should use -

Only()

Maxstring()

Concat()

Regards,

Re: Performance Impact

cesaraccardi — Thu, 21 May 2015 10:58:03 GMT

Ok thanks, I think I understand now.

If the goal is to reduce a list of text values to a single value then I would suggest to use Only() as it is a basic aggregation function and doesn't have any additional processing to find out what is the maximum value, like maxstring() for example.

Now regarding Concat() the result would not be the same as Only() unless if you include a DISTINCT parameter inside the function which I suspect (not 100% sure) will be less performant than Only().

Hope this helps,

Cesar

Re: Performance Impact

cesaraccardi — Thu, 21 May 2015 11:00:08 GMT

By the way, I am assuming all the values on the field you are aggregating are the same. Please let me know if this is not the case.

Re: Performance Impact

rajeshvaswani77 — Thu, 21 May 2015 11:05:01 GMT

Overall the Set Expression will give you a performance benefit.

thanks,

Rajesh Vaswani