Security Cost in Analysis Service Tabular
Applying security roles to a SSAS Tabular database might impact query performance. This article describes existing issues and possible workarounds. This is an advanced article, a good knowledge of storage engine and formula engine is required.
When you define a security role in a SQL Server Analysis Services Tabular database, you can apply a filter to every table in the data model. You can write an expression that is evaluated in the row context of the table. Thanks to filter context propagation, if you filter the Product table, you also filter the Sales table if a relationship exists between the two tables.