The Report View is primarily used for developing visualizations, but it also supports modeling features, such as the creation of user-defined hierarchies. In the following screenshot of a DirectQuery dataset, the Customer City column of the Customer table is selected from the fields list:
Modeling options in Report View
The Data Category and Default Summarization properties for the Customer City column have been set to City and Don't summarize, respectively. The Modeling tab of the Report View provides both import and DirectQuery datasets with access to all common modeling features, such as managing relationships, creating new DAX Measures, and accessing RLS roles.
Note that the New Table option is grayed out for DirectQuery datasets since DAX-calculated tables are exclusively able to import models. However, as explained in both the chapters Chapter 1, Planning Power BI Projects and
Chapter 2, Connecting to Sources and Transforming Data with M, DAX-calculated columns and tables should be rarely used. M queries, SQL views, and data warehouse objects are almost always preferable alternatives to support the needed columns and tables.
In terms of data modeling, the Relationships View and the following Manage relationships dialog are the most fundamental interfaces as these definitions impact the behavior of DAX Measures and report queries:
Manage relationships dialog
Relationships can be created, edited, and deleted from the Manage relationships dialog. For larger models with many tables and relationships, the dataset designer can utilize both the Manage relationships dialog and the Relationships View.
Dynamic Management Views (
DMVs), such as
TMSCHEMA_RELATIONSHIPS, can be used to analyze Power BI datasets, just as they're used with other SQL Server products. To get started, simply open the DAX Studio application while the Power BI Desktop (PBIX) file is open and connect to the running dataset. You can then query the DMVs (that is,
select * from $SYSTEM.TMSCHEMA_RELATIONSHIPS). For longer-term projects, it can be worthwhile to create a Power BI dataset that exclusively retrieves from DMVs data and supports updated documentation reports, such as the tables, columns, and measure definitions included in a dataset. An example of this is included in the
Microsoft Power BI Cookbook (
https://www. packtpub.com/big-data-and-businessintelligence/microsoft-power-bi-cookbook).
