Joey D’Antoni needed to use the Dedicated Administrator Connection:
Because as shown in the image above, the table in question is a system_table, in order to query it directly, you need to use the dedicated administrator connection (DAC) in SQL Server. The DAC is a piece of SQL Server that dedicates a CPU scheduler, and some memory for a single admin session. This isn’t designed for ordinary use–you should only use it when your server is hosed, and you are trying to kill a process, or when you need to query a system table to answer a twitter post. The DAC is on by default, with a caveat–it can only be accessed locally on the server by default. This would be connected to a server console or RDP session on Windows, or in the case of a container, by shelling into the container itself. However, Microsoft gives you the ability to turn it on for remote access (and you should, DCAC recommends this as a best practice), by using the following T-SQL.
Read on to see how, as well as what else you’d need to do to get it working.