Book Image

QlikView for Developers Cookbook

By : Stephen Redmond
Book Image

QlikView for Developers Cookbook

By: Stephen Redmond

Overview of this book

QlikView has been around since 1993, but has only really taken off in recent years as a leader in the in-memory BI space and, more recently, in the data discovery area. QlikView features the ability to consolidate relevant data from multiple sources into a single application, as well as an associative data model to allow you to explore the data to a way your brain works, state-of-the-art visualizations, dashboard, analysis and reports, and mobile data access. QlikView for Developers Cookbook builds on your initial training and experiences with QlikView to help you become a better developer. This book features plenty of hands-on examples of many challenging functions. Assuming a basic understanding of QlikView development, this book provides a range of step-by-step exercises to teach you different subjects to help build your QlikView developer expertise. From advanced charting and layout to set analysis; from advanced aggregations through to scripting, performance, and security, this book will cover all the areas that you need to know about. The recipes in this book will give you a lot of the information that you need to become an excellent QlikView developer.
Table of Contents (19 chapters)
QlikView for Developers Cookbook
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Denormalizing for performance


Good transactional database design suggests that data tables should be normalized, at least to third normal form. But this is not necessarily the most efficient for QlikView.

In a QlikView data model, the more association links between two fields, the longer it will take to calculate the result of one versus the other.

By that logic, it might make sense to consider that a single table model is the most efficient in QlikView. But that is not necessarily the case either.

Getting ready

Generate QVDs created in the Reducing the number of distinct values recipe.

How to do it…

These steps demonstrate how to denormalize for performance:

  1. Create a new QVW file in the same folder as QVDs and load the following script:

    Sales:
    LOAD //SalesID, 
         Hour(TransactionDate) As TransHour,
         DateID, 
         ProductID, 
         CustomerID, 
         Discount, 
         Quantity, 
         SalePrice, 
         Sales
    FROM
    [Sales.qvd]
    (qvd);
    
    Calendar:
    LOAD DateID, 
         Date, 
         Year, 
         Month, 
     ...