QlikView 11 for Developers: This book is smartly built around a practical case study – HighCloud Airlines – to help you gain an in-depth understanding of how to build applications for Business Intelligence using QlikView. A superb hands-on guide.

The main difference between QlikView and other BI solutions is the associative user experience. Where traditional BI solutions use predefined paths to navigate and explore data, QlikView allows users to take whatever route they want. This is a far more intuitive way to explore data. QlikTech describes this as "working the way your mind works."

An example is shown in the following image. While in a typical BI solution, we would need to start by selecting a Region and then drill down step-by-step through the defined drill path, in QlikView we can choose whatever entry point we like—Region, State, Product, or Sales Person. We are then shown only the data related to that selection, and in our next selection we can go wherever we want. It is infinitely flexible.

Additionally, the QlikView user interface allows us to see which data is associated with our selection.

For example, the following screenshot (from QlikTech's What's New in QlikView 11 demo document) shows a QlikView Dashboard in which two values are selected. In the Quarter field, Q3 is selected, and in the Sales Reps field, Cart Lynch is selected. We can see this because these values are green, which in QlikView means that they have been selected. When a selection is made, the interface automatically updates to not only show which data is associated with that selection, but also which data is not associated with the selection. Associated data has a white background, while non-associated data has a gray background. Sometimes the associations can be pretty obvious; it is no surprise that the third quarter is associated with the months July, August, and September. However, at other times, some not-so-obvious insights surface, such as the information that Cart Lynch has not sold any products in Germany or Spain. This extra information, not featured in traditional BI tools, can be of great value, as it offers a new starting point for investigation.

QlikView's core technological differentiator is that it uses an in-memory data model, which stores all of its data in RAM instead of using disk. As RAM is much faster than disk, this allows for very fast response times, resulting in a very smooth user-experience.

In a later part of this chapter, we will go a bit deeper into the technology behind QlikView.

There is also a difference between QlikView and traditional BI solutions in the way it is typically rolled out within a company. Where traditional BI suites are often implemented top-down—by IT selecting a BI tool for the entire company—QlikView often takes a bottom-up adoption path. Business users in a single department adopt it, and its use spreads out from there.

Often, a business user will decide to download QlikView to see if he can solve a business problem. When other users within the department see the software, they get enthusiastic about it, so they too download a copy. To be able to share documents, they decide to purchase a few licenses for the department. Then other departments start to take notice too, and QlikView gains traction within the organization. Before long, IT and senior management also take notice, eventually leading to enterprise-wide adoption of QlikView.

QlikView facilitates every step in this process, scaling from single laptop deployments to full enterprise-wide deployments with thousands of users. The following graphic demonstrates this growth within an organization:

As the popularity and track record of QlikView have grown, it has gotten more and more visibility at the enterprise level. While the adoption path described before is still probably the most common adoption path, it is not uncommon nowadays for a company to do a top-down, company-wide rollout of QlikView.

But where should we click? QlikView lets us select data in a number of ways. A common method is to select a value from a list-box. This is done by clicking in the list-box.

Let's switch to the How QlikView works tab to see how this works. We can do this by either clicking on the How QlikView works tab on the top of the sheet, or by clicking on the Get Started button.

The selected tab shows two list boxes, one containing Fruits and the other containing Colors. When we select Apple in the Fruits list-box, the screen automatically updates to show the associated data in the Colors list-box: Green and Red. The color Yellow is shown with a gray background to indicate that it is not associated, as seen below, since there are no yellow apples. To select multiple values, all we need to do is hold down Ctrl while we are making our selection.

Besides selections in list-boxes, we can also directly select data in charts. Let's jump to the Dashboard tab and see how this is done. The Dashboard tab contains a chart labeled Number of Movies, which lists the number of movies by a particular actor. If we wish to select only the top three actors, we can simply drag the pointer to select them in the chart, instead of selecting them from a list-box:

Because the selection automatically cascades to the rest of the model, this also results in the Actor list-box being updated to reflect the new selection:

Of course, if we want to select only a single value in a chart, we don't necessarily need to lasso it. Instead, we can just click on the data point to select it. For example, clicking on James Stewart leads to only that actor being selected.

While list-boxes and lassoing are both very convenient ways of selecting data, sometimes we may not want to scroll down a big list looking for a value that may or may not be there. This is where the search option comes in handy.

For example, we may want to run a search for the actor Al Pacino. To do this, we first activate the corresponding list-box by clicking on it. Next, we simply start typing and the list-box will automatically be updated to show all values that match the search string. When we've found the actor we're looking for, Al Pacino in this case, we can click on that value to select it:

Sometimes, we may want to select data based on associated values. For example, we may want to select all of the actors that starred in the movie Forrest Gump. While we could just use the Title list-box, there is also another option: associated search.

To use associated search, we click on the chevron on the right-hand side of the search box. This expands the search box and any search term we enter will not only be checked against the Actor list-box, but also against the contents of the entire data model. When we type in Forrest Gump, the search box will show that there is a movie with that title, as seen in the screenshot below. If we select that movie and click on Return, all actors which star in the movie will be selected.

Inevitably, when exploring data in QlikView, there comes a point where we want to save our current selections to be able to return to them later. This is facilitated by the bookmark option. Bookmarks are used to store a selection for later retrieval.

Creating a new bookmark

To create a new bookmark, we need to open the Add Bookmark dialog. This is done by either pressing Ctrl + B or by selecting Bookmark | Add Bookmark from the menu.

In the Add Bookmark dialog, seen in the screenshot below, we can add a descriptive name for the bookmark. Other options allow us to change how the selection is applied (as either a new selection or on top of the existing selection) and if the view should switch to the sheet that was open at the time of creating the bookmark. The Info Text allows for a longer description to be entered that can be shown in a pop-up when the bookmark is selected.

Retrieving a bookmark

We can retrieve a bookmark by selecting it from the Bookmarks menu, seen here:

Fortunately, if we end up making a wrong selection, QlikView is very forgiving. Using the Clear, Back, and Forward buttons in the toolbar, we can easily clear the entire selection, go back to what we had in our previous selections, or go forward again. Just like in our Internet browser, the Back button in QlikView can take us back multiple steps:

Cyclic Groups are defined by developers as a list of dimensions that can be switched between users. On the frontend, they are indicated with a circular arrow. For an example of how this works, let's look at the Ratio to Total chart, seen in the following image. By default, this chart shows movies grouped by duration. If we click on the little downward arrow next to the circular arrow, we will see a list of alternative groupings. Click on Decade to switch to the view to movies grouped by decade.

Drill down Groups are defined by the developer as a hierarchical list of dimensions which allows users to drill down to more detailed levels of the data. For example, a very common drill down path is Year | Quarter | Month | Day. On the frontend, drill down groups are indicated with an upward arrow.

In the Movies Database document, a drill down can be found on the tab labeled Traditional OLAP. Let's go there.

This drill down follows the path Director | Title | Actor. Click on the Director A. Edward Sutherland to drill down to all movies that he directed, shown in the following screenshot. Next, click on Every Day's A Holiday to see which actors starred in that movie. When drilling down, we can always go back to the previous level by clicking on the upward arrow, located at the top of the list-box in this example.

Containers are used to alternate between the display of different objects in the same screen space. We can select the individual objects by selecting the corresponding tab within the container. Our Movies Database example includes a container on the Analysis sheet.

The container contains two objects, a chart showing Average length of Movies over time and a table showing the Movie List, shown in the following screenshot. The chart is shown by default, you can switch to the Movie List by clicking on the corresponding tab at the top of the object.

On the time chart, we can switch between Average length of Movies and Movie List by using the tabs at the top of the container object.

The Windows application we used earlier to navigate and analyse the data in Movies Database can not only be used to consume content, but it is also the main tool with which to create QlikView documents. As this book is focused on developers, this will be the main focus for the remaining chapters.

When QlikView deployments expand, it becomes impractical to update and distribute files manually. Also, data is loaded into RAM when using a local Windows application to open QlikView files. When working with huge amounts of data, each PC would also need a huge amount of RAM. This might work for developer PCs, but it is hardly a cost-effective solution to outfit each user in the organization with large amounts of RAM.

Fortunately, QlikView has three components to mitigate these potential roadblocks to broader adoption:

QlikView documents can be consumed in multiple ways. While this book mainly focuses on the QlikView Desktop Windows application, it is interesting to take note of the other possibilities for deployment:

When going through this list of clients, you probably noticed that the AJAX client is the most versatile of all clients. While it hasn't always been that way, nowadays, the visual and functional differences between the AJAX client and the ActiveX client are small enough for the AJAX client to be considered the preferred client for consumption of QlikView documents by users.