Book Image

QlikView Unlocked

By : Andrew Dove, Roger Stone
Book Image

QlikView Unlocked

By: Andrew Dove, Roger Stone

Overview of this book

QlikView Unlocked will provide you with new insights to get the very best from QlikView. This book will help you to develop skills to work with data efficiently. We will cover all the secrets of unleashing the full power of QlikView, which will enable you to make better use of the tool and create better results for future projects. In the course of this book, we will walk you through techniques and best practices that will enable you to be more productive. You will gain quick insights into the tool with the help of short steps called ”keys,” which will help you discover new features of QlikView. Moving on you will learn new techniques for data visualization, scripting, data modeling, and more. This book will then cover best practices to help you establish an efficient system with improved performance. We will also teach you some tricks that will help you speed up development processes, monitor data with dashboards, and so on. By the end of this book, you will have gained beneficial tips, tricks, and techniques to enhance the overall experience of working with QlikView.
Table of Contents (16 chapters)
QlikView Unlocked
About the Authors
About the Reviewers
Hidden Image List

Cached expressions

One of the ways to get a stunning performance from the QlikView engine is to cache all its expression results for each selection made (well, all that will fit in available memory, that is).


If you Google the definition of cache, you'll get something similar to this:

Noun: cache

"Computers: A temporary storage space or memory that allows fast access to data".

This means that every time an expression needs to be recalculated, the cache is used to check whether the same expression has been used with the current selection criteria. If it has, the result is taken from the cache rather than being recalculated again. However, take a look at these three expressions:

  • Sum(TotalPrice)

  • sum(TotalPrice)

  • sum (TotalPrice)

All the three expressions stated here give exactly the same result, but each is executed and cached individually. This is because there are subtle differences in each: the second and third have a lowercase "s" in the Sum function, and the third also has a space between the...