topic Re: now() vairable - slow down refresh in QlikView

now() vairable - slow down refresh

samuel_brierley — Wed, 25 Nov 2020 16:16:04 GMT

hi all,

im using a now() vairable to try and imitate a live system however the refewsh rate of now() is causing performance issues, is there a way i can slow down the refresh rate? ideally to every 15 mins?

thanks

Re: now() vairable - slow down refresh

swuehl — Fri, 01 Apr 2016 14:00:09 GMT

Not that I know of.

I think this performance impact is also documented in the manual / Help, without mentioning any setting to control the refresh.

Re: now() vairable - slow down refresh

samuel_brierley — Fri, 01 Apr 2016 14:17:12 GMT

didnt think it was,

is there another solution whereby i make a filter based on the variable?

the problem is i have a few charts that all contain set analysis using the variable, this is slow however if i could make the select in a list box that will be reflected on all charts and be much quicker, im just not sure if thats possible./

Re: now() vairable - slow down refresh

swuehl — Fri, 01 Apr 2016 14:21:19 GMT

Not sure I understand your setting. Could you upload a small sample QVW?

Re: now() vairable - slow down refresh

samuel_brierley — Fri, 01 Apr 2016 14:26:23 GMT

sorry ive thought of the solution just not how to do it....

is it possible to run a macro every 15 minutes (scheduled) that filters on dimension 15_Time where the records are greater than variable vLastUpdate_Time?

Re: now() vairable - slow down refresh

swuehl — Fri, 01 Apr 2016 14:37:54 GMT

Sorry, I still don't understand.

Do you expect either your dimension field values or your variable to change inbetween?

Or why do you want to do the selection every 15 min?

Re: now() vairable - slow down refresh

samuel_brierley — Fri, 01 Apr 2016 14:40:42 GMT

my variable is set to now() which updates itself so by placing the variable into set analysis in any chart i am imitating a live system. this method gets quite slow so im looking to have a macro run every 15 mins (time intervals in my data) i can make a selection based on the now variable.

Re: now() vairable - slow down refresh

psankepalli — Fri, 01 Apr 2016 14:44:21 GMT

I am not sure I understand correctly, is it possible for you to load model application with the variable and expression. so that you can get a prompt answer here.

Re: now() vairable - slow down refresh

swuehl — Fri, 01 Apr 2016 14:44:57 GMT

And you are accessing the QVW using the desktop client or via browser / Ajax client?

Re: now() vairable - slow down refresh

swuehl — Fri, 01 Apr 2016 15:00:14 GMT

Still not sure if I understand your setting,but from reading your above descriptions:

Create a variable v15Min

=Div(Minute(Now()),15)

Then create a variable OnChange trigger with a Selection - Select in field action to select in your list box.

This should still poll the time continuously, but only make selections once every 15 mins.

Note that using Now() may show issues when using the Ajax client.

Re: now() vairable - slow down refresh

samuel_brierley — Fri, 01 Apr 2016 17:55:44 GMT

thanks swuehl this is definelty the solution.

ran into another issue though, i cant seem to get me search string correct, can you take a look at why my selection wont work correctly, its almost definetly syntax. ive created a button to replicate the selection in field action.

what my button should do is select all 15_time that are less than vLastUpdate.

tjhanks

Re: now() vairable - slow down refresh

swuehl — Sun, 03 Apr 2016 21:35:22 GMT

This search string seems to work for me:

='>'&vLastUpdate