Categories: SQL Server

Restarting SQL Server after adding a new SQL login

At a project, we asked if we could get a SQL Server login/user so we could make a connection from an Apache Airflow pipeline to the SQL Server instance. The answer was: “No, because then we would need to restart the server”. This sounded a bit strange, because I’ve never had to restart the SQL Server instance to add a new user.

I double checked on Google and I couldn’t find any info on why you should need to reboot the server. I asked on Twitter, and even no-one of the #SQLFamily could find a reason. I was starting to question the sanity of the admins at the project. However, after a quick discussion we finally discovered the reason why:

SQL Server authentication was not enabled on the instance.

The default authentication mode when installing SQL Server is Windows Authentication only:

If you want SQL Server authentication, you need to explicitly enable it during set-up (so no next-next-finish). In this case, it wasn’t the case. You can switch to mixed mode later on, but you might’ve guessed it: this requires a restart of the SQL Server instance.

All this learned me one important lesson: when someone gives you a surprising answer, don’t make assumptions. They probably have a good reason.


------------------------------------------------
Do you like this blog post? You can thank me by buying me a beer 🙂
Koen Verbeeck

Koen Verbeeck is a Microsoft Business Intelligence consultant at AE, helping clients to get insight in their data. Koen has a comprehensive knowledge of the SQL Server BI stack, with a particular love for Integration Services. He's also a speaker at various conferences.

View Comments

  • My understanding is SQL authentication is inherently less safe than using Windows Login. With SQL Authentication anyone can log in from anywhere as long as they are able to contact the server.

    • Your last sentence is also the reason why it's sometimes useful to have SQL authentication. If AD is down, you can still log in to your server.

Recent Posts

Book Review – Agile Data Warehouse Design

I recently read the book Agile Data Warehouse Design - Collaborative Dimensional Modeling, from Whiteboard…

5 days ago

Cloudbrew 2024 – Slides

You can find the slides for the session Building the €100 data warehouse with the…

1 week ago

Book Review – Microsoft Power BI Performance Best Practices

I was asked to do a review of the book Microsoft Power BI Performance Best…

1 month ago

Create a Numbers Table in Power Query

This is a quick blog post, mainly so I have the code available if I…

1 month ago

Microsoft finally adds Tenant Switcher for Fabric / Power BI

Praise whatever deity you believe in, because it's finally here, a tenant switcher for Microsoft…

1 month ago

Book Review – Humanizing Data Strategy by Tiankai Feng

This book was making its rounds on social media, and the concept seems interesting enough…

1 month ago