Building your data model consists of how you combine your data before you analyze it. There are numerous factors to take into account when determining a data model structure – the amount of data, type of data, granularity of the data, number of data sources, and so on. The Data Source page is where we will set up how Tableau interprets the data from the data source. The settings we modify on this page tell Tableau where to find the data (for example, network location, server name, and more) and what data is available, and it allows us to customize the data that is brought in (for example, change field names, create new columns based on calculations, and more).
Tableau allows you to easily combine data from different sources. Here are the various ways in which we can join data together on the Data Source page.

• Data from a single source: The workflow when needing only one table is simple – drag the table name (or double-click) from the left pane onto the canvas. You will only need to make one data connection.
• Data from a single database but multiple tables: When using multiple tables in the same database, the canvas gives you the ability to join and union tables. You will only need to make one data connection.
• Data from multiple databases and multiple tables: If you are connecting to multiple databases and need to use data from many tables then you can use cross-database joins.
• Data blending: This shows data from two different sources that are at a different grain. You will need to make multiple data connections.

Now that we have a general overview of what we can do on the Data Source page, let's move on to how we can further refine our data model.