WHAT IS DATA SHAPE AND WHY DOES IT MATTER IN TABLEAU?

How can data have a shape?  It's made up of numbers!  When working with Tableau it's all about the shape of the data.

What does tall vs wide mean?

The two tables below contain the same information but in different shapes or formats.

Tall data: 2 dimensions, 1 measure

Wide data: 1 dimension and 4 measures

Why does data shape matter?

Data shape matters when you are trying to build your visualization.  In Tableau it’s generally better if the data is tall rather than wide.  Not only are the visualizations easier to build but Tableau can compute tall tables faster than wide tables.  You can get to the same end visualization but the steps to get there will be different.

Example: Stacked bar graph

Tall Data Example
Columns: SUM(Avg Loan Amount)
Rows: State Name
Color: Loan Type Name

In most cases when you have wide data you need to use measure names and measure values.  Measure names and measure values are most often used when visualizing more than 1 measures in a visualization.  Since the wide data source has 4 measures opposed to 1 we will have to use measure values.

The measure values shelf combines all the measures and treats them as one measure or (green) pill.  In order to only include particular measures from the data source a Measure Names filter gets added to the filters shelf.

Wide Data Example
Columns: Measure Values
Rows: State Name
Color: Measure Names

The tall and wide data sets end up with the same visualization but the steps to get there are easier with the tall data set.