Qlikview Best Practices - 1 - Cache Friendly Expressions

This is the first post of the Qlikview Best Practises series in this blog. In this series of blog posts I aim to share the best practises I personally use and highly suggest in Qlikview Projects.

An expression in Qlikview is used to decrease the size of the data you are discovering. This is similar to what we use in Ansi sql as “query”. Initially you have the full data set to analyse but when you apply an expression in your chart you will restrict the rows available in data set. For example if you want to display sum of sales information for one region, you would use the following script:

Sum({$<Region={‘America’}>} Sales)

Expressions have a huge affect on chart calculation time. However once Qlikview calculates an expression it saves the result in a cache along with the state. This means that when you make a selection and chart does the calculation, for that selection and expression, Qlikview creates a cache slot. When you make another selection, then Qlikview saves it in another cache slot. So, Qlikview creates a cache unit for every expression and selection state. It even creates a new cache for expressions typed differently. Any extra space, character capitalization difference in expressions will cause a new calculation and a new cache slot.

Making sure you always type the same expression in the same way is a hard to achieve task and cost of not doing so is considerably high. To mitigate this you can store your expressions in variables and load them from an excel spreadsheet. By doing this you will make sure yourself that you are using the same expression for the same purpose across your documents.

Keep in Mind When Developing Qlikview Applications

While developing Qlikview projects, from time to time I load new data from data sources. And I have a standard of coding; there are things to be considered each time I load data or create a new app. I would like to keep the records of what I should take into consideration when creating a new app. The list will not be as it is when I am writing this post, I will be adding new items, whenever I find new ideas worth to mention here.

Qlikview Set Analysis and Point in Time Reporting

Qlikview's one of the most beautiful and hard to implement feature is Set Analysis functionality without any doubt. As long as it is implemented efficiently customer satisfaction tend to increase whilst in case of excessive and ineffective usage it is inevitable to have performance issues.

Qlikview Document Integration - how to hide ajax toolbar or objects on it

Qlikview applications can be viewed in a web application using document/iframe integration. After integration of the document an ajax tool bar appears on top of the document. Although it contains several useful controls, one might think it is space occupying and also useless. In this case you are free to hide this tool bar itself or icons on it.

How To Create/Load a Qlikview Object From Asp.Net Codebehind using Workbench

In this blog post you will find a short c# code snippet allowing QlikView Workbench developers to create a new QlikView Object on Visual Studio IDE's code behind.