A master view is the default configuration of a smart, activated after you purchase a smart. It defines the geographical scope and time limits of the data you subscribed to, if applicable.
In case you need to access externally all the data available within it, including all columns and default granularity, you can directly connect to this view.
However, keep in mind that many BI tools may be unable to work with heavy datasets or that the connection may be slow and costly. If you are not interested in the information provided by each and every column, or you can benefit from focusing on a specific period, geography or any other filtering option, we strongly recommend you create custom views to improve performance and reduce costs and data weight.