topic Re: Expression on variable in QlikView

Expression on variable

Wed, 18 Jan 2012 14:10:28 GMT

Hi guys, i've a little bit question......

I use to create my qv project using variables, in these variable i write the common expressions, so i don't need to re-write more than one the same expression if it's needed in charts located in different places/tab (i put in the expressions only the variable that contains the expression, it's faster)

The question is :

When i load by browser the qv document, it makes the calculations of all expressions inside my variables ?

I.E.

I've twice variables witch contains twice expressions, the first variable is on a chart on first tab, the second on a chart in the second tab, when i load the document the first time only the first tab is opened, right....but....the time spent by qv on loading the doc, include the calculation of both expressions or only the first of the first tab ?

I hope it's clear.

thx a lot.

bye.

Expression on variable

RSvebeck — Wed, 18 Jan 2012 14:28:34 GMT

The expressions are not calculated during loading, they are calculated when the object is visible on your screen. Expressions on objects on other sheets are not calulated. Does this answer your question? Regards Robert

Expression on variable

Thu, 19 Jan 2012 14:13:48 GMT

I'm not sure.....ok, the expressions are calculated when chart is visible, but my expressions are inside the variable, so the question could be : all expressions located inside the variables are calculated when the document is loaded ?

Expression on variable

srinivasa1 — Thu, 19 Jan 2012 14:18:18 GMT

Hi,

You can try with set variables in etl while loading.hope it will solve your pbm.

srini

Re: Expression on variable

RSvebeck — Thu, 19 Jan 2012 14:22:20 GMT

I am talking about variables as expressions when they are used in objects like charts and textboxes. These variable can be created in the load script, and even be loaded in the load script.

But variables can also be used in the load script. In this case, the expression is also used in the load script.

Is your question about expressions as variables when they are used in objects or when they are used in the load script?

Reg. Robert

Expression on variable

Thu, 19 Jan 2012 15:37:04 GMT

Is your question about expressions as variables when they are used in objects or when they are used in the load script?

The first one.

Re: Expression on variable

RSvebeck — Fri, 20 Jan 2012 08:49:42 GMT

Ok. So this means that the variables you have - containing expressions - are only used in objects like charts etc on actual sheets in your Qlikview document.

This also means that those expressions are only calculated when those objects are visible for the user. And they get recalculated every time you make a change in the data, like limiting a dimension etc.

If you have the same variable in two objects on two sheets, only the object that is visible gets calculated. You may have 1000 objects using the same variable/expression, but only the visible ones will take CPU power.

If you use the same variable in several different objects that are all visible, I am not sure if the expression is calculated several times or if Qlikview is smart enough to understand that it is the same calculation. I would guess strongly that Qlikview is smart in this case and that the calculation is only done once.

Regards Robert