Virtual table relationships are DAX expressions implemented to filter a table from another table when a relationship doesn't exist between these tables. Report visualizations can then be constructed using both tables (and their related tables) and the DAX measures will update as though a normal relationship is defined. Virtual relationships are often used to address disparate grains of tables and to leverage performance segmentation tables.
Although physical relationships are the preferred long term solution for both performance and manageability, virtual relationships provide an attractive alternative when physical relationships are not feasible. In this recipe we provide virtual relationship examples of using a custom performance segmentation table and an aggregated table.