topic Re: Impact of Unwanted Variables on Performance in QlikView

Impact of Unwanted Variables on Performance

Anonymous — Thu, 20 Aug 2015 07:53:54 GMT

Hi All,

We are facing performance issue in our application of around 5GB.

While analysing, expressions, variables, if statements, we found that there are around 15 unwanted variables along with nested If-else and Pick Match along with colormix formula.

Can anyone please tell me that whether the Unwanted Variables has any impact on Performance.

Please let me know your comments on same.

Thanks & Regards,

Re: Impact of Unwanted Variables on Performance

Anonymous — Thu, 20 Aug 2015 08:43:48 GMT

gwassenaar‌, mby‌,

Any comments on above query.

Re: Impact of Unwanted Variables on Performance

Peter_Cammaert — Thu, 20 Aug 2015 08:52:20 GMT

Unwanted variables may have a substantial impact on performance as they will be recalculated all the time and you clearly do not want that. Unused variables IMHO have no impact at all.

BTW be a little more patient. Most of these high-profile community members have a paying job and no strict obligation to be on-line at any time. Someone will pick up your question sooner or later, as you can see now...

Re: Impact of Unwanted Variables on Performance

swuehl — Thu, 20 Aug 2015 09:18:16 GMT

MK, just for clarification, could you elaborate what you mean with 'unwanted' variable, especially compared to an 'unused' variable?

Re: Impact of Unwanted Variables on Performance

Anonymous — Thu, 20 Aug 2015 09:30:16 GMT

it should be unused variables.

Re: Impact of Unwanted Variables on Performance

Anonymous — Thu, 20 Aug 2015 09:43:27 GMT

Thanks for your reply.

In between what is IMHO.

Re: Impact of Unwanted Variables on Performance

Peter_Cammaert — Thu, 20 Aug 2015 10:34:38 GMT

IMHO = In My Humble Opinion

AFAIK = As Far As I Know

IIRC = If I Remember Correctly

BTW = By The Way

PFA = Please Find Attachment

FYI = For Your Information

and others can be found here: Internet Slang

There is a very extensive list of all acronyms on Wikipedia: List of acronyms - Wikipedia, the free encyclopedia

You're right, I'm sorry. I shouldn't be using these. But it saves me some time when typing a reply

Re: Impact of Unwanted Variables on Performance

Anonymous — Thu, 20 Aug 2015 11:48:51 GMT

First, unused fields/variables should have little to none impact on performance, but only when the hardware is adequately "sized".

Do remember that QlikView is a "in-memory" tool, and once you open your application, most or all of your data will be loaded into memory.

A good rule of thumb should be that once you have created your app, remove all unused and unneeded data.

Second, if's in expressions should changed to use set analysis as far as possible. Set analysis reduces the amount of data inside the QlikView Engine, while if's are evaluating each row in the total dataset "outside" the QlikView Engine - from what I know this actually is done client side by javascript, which is MUCH slower (I could be wrong on my last statement, but it IS must slower).

Hope this helps!