Referential integrity is set via Data > [Data Source] >Assume Referential Integrity. When selected, Tableau only includes a joined table if it is specifically referenced by fields in the view. As a result, queries to the data source are simplified and performance improves.
Referential Integrity assumes every key value in one table exists in a corresponding key in another table.
Ideally, referential integrity should be set at the database level as this will improve database performance as well as performance in Tableau. When referential integrity is set at the database level, Tableau will not include any reference to the joined table (unless that table is specifically referenced by fields in the view) even if Data > [Data Source] > Assume Referential Integrity is not selected.
The following example will explore how a query is...
