Reza Rad has two posts covering connection types in Power BI. First up is an overview of data importation:
Power BI is one of the BI tools in the market that supports more than one type of connection. Each connection type has pros and cons. In this section, we are going to cover everything about Import Data or Scheduled Refresh type of connection. You will learn briefly how Power BI stores data into xVelociy in-memory engine, and what are pros and cons of this method in detail.
In the last post, you learned about Import Data or Scheduled Refresh as a connection type. In this post, you’ll learn about the second type of connection named; DirectQuery. This type of connection is only supported by a limited number of data sources, and mainly targets systems with a huge amount of data. DirectQuery is different from another type of connection which I’ll talk about it in the next post named Live Connection.
Understanding when (and how) to use each is important for long-term success in Power BI.