Overview of data engine architecture

Whenever you launch Power BI Desktop, an Analysis Service process is launched on your local machine. Figure 3.1 shows the service running in Task Manager.

Figure 3.1 – Analysis Services service in Task Manager

This engine, referred to as VertiPaq, is where the imported and transformed data resides for a Power BI dataset. The term dataset has been switched for semantic model, which was the original name for SQL Server Analysis Services. This process or service stores the data in the column structure in a compressed mode. Included with the structure are column indexes, dictionaries, and hierarchies. We will see more on this in the sections on DAX Studio. DAX Studio can display the actual storage structure for column data and all the subsets of the column structure.

There are two engines that process queries and return data in visualizations in Power BI. The formula engine processes the query request, and the...