![]() Joins require the user to specify the join type and clause, whereas relationships in the logical layer are automatic. The result is an extended single table with all fields included. In previous versions of Tableau the data model consisted only of a physical layer where the user could set up the normal joins and unions between the tables. Consequently, Tableau figures out how to handle different levels of detail and simplifies the aggregation of calculations such as averages or totals. ![]() ![]() Tableau will also apply some performance options so that the data model works properly, but just in the same way as with related fields, users can modify these settings to match their needs. Tableau will choose the fields to create the relationships between the tables, although it is also possible to update manually or even create a set of related fields. Starting in the data source tab from Tableau Desktop, we find that the default top-level layer is the logical layer.Īfter dragging some tables to the pane, we see that Tableau automatically creates the relationships between these tables and instead of a join operator we find some related fields. Let’s take a deeper look at these two layers: Each table in the logical layer contains one or more tables in the physical layer.įigure 1: Tableau 2020.2 Data Model Scenario ![]() After that, a physical layer in which we will be able to combine data using joins. These new modelling capabilities provide different levels of detail: first, a logical layer in which the associations among the different tables are built. Tableau’s 2020.2 version already allows us to explore one of the most anticipated features: a new approach for data modelling that will make the analysis of data across multiple tables much easier. Up until now, Tableau had been considered strictly a visualization tool in terms of data processing, Tableau Desktop offered the possibility of combining different data sources or tables using joins and data blending, but the analyst may need to build a data model to format the data. ![]()
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