Adding a Database with Polybase External Tables to Always On Availability Group


Introduction

I was asked to add a database with PolyBase External Tables to Always On Availability Group. I thought it would be a straightforward approach, but it got tricky when I learned that one of the prerequisites of PolyBase is that a master key is needed. This article describes how to add a database with PolyBase External Objects to an Availability Group.

Explanation

Our application databases were hosted on SQL Server 2016, and the application team used ETL jobs to import data from ODBC data sources, like Vertica, to SQL Server 2016. When the application team learned about the SQL