Tableau

Common types of data sets

What is a data set?

A data set (sometimes referred to as data source, or database) in the context of Tableau, contains the data used to build visualizations. Every bar chart, scatter plot, or line chart you see in Tableau has a connected database or spreadsheet that supplies the data.

You can learn more about different data source types below.

Most Common:

• Spreadsheets

• Relational databases

  • Relational databases store data in multiple tables, with each row assigned a unique identifier. Users pull data from different tables together using Structured Query Language (SQL). The "relational" aspect indicates a logical connection between different tables.

• Cloud Data

  • Sometimes, organizations prefer to store their data in the cloud so they do not have to support on-premises servers. This includes data stored in such places as Amazon Web Services or Microsoft Azure.

• Tableau also connects to spatial files for mapping, such as .kml or .shp, and statistical files created in R.

Complete list of supported data connections and files in Tableau

What happens when Tableau Desktop connects to a data set?

When users connect to Tableau, the data fields in their data set are automatically assigned a role and a type.

Role	Type
A field can be assigned to a Dimension role or a Measure role.	The field's data type defines if the field is, for example, a string, integer, or date.
We'll learn more about dimensions and measures in the next lesson.	Data types can be changed by the user if Tableau does not assign the type appropriately. Any changes are saved in a Tableau data source (.tds) file as metadata—which is a set of data that describes other data.