Several years ago, I heard about a new product coming in Azure that would provide an IaaS (infrastructure as a service) VM to run SQL Server, with Microsoft managing most of the admin tasks for the instance, like patching and backups. That didn't seem like a big load to me, and I wondered if anyone would actually pay for this product. After all, don't most companies find managing patches and backups fairly easy to manage?

That product became Azure SQL Managed Instance, and I've been surprised at the adoption. Quite a few clients have adopted this as a way to lift and shift (mostly) to the cloud in an easy fashion without the restrictions of Azure SQL Database. This looks like a "normal" on-premises SQL Server, and there are both high-performance (Business Critical tier) and average-performance (General Purpose tier) versions of the product that let you choose what level of price/performance you need to achieve.

I'm curious today, and I have a question. What are your impressions of Managed Instance (MI)? Whether you use it, you have heard of it, or if you just read this description. Give me a few thoughts on whether this makes sense, performs well, or has issues you need (or wish would be) addressed.

I've heard there are some issues with I/O, but I also have clients who find it performs very well for them. I hear similar things from on-premises SQL Server instances, so I often think that either the software is designed well or the hardware architecture doesn't match the workload. There have been a lot of enhancements to MI since its release, including the ability to backup and restore to/from SQL Server 2022.

There is even an offer from Microsoft that lets you try out MI for free (for a period of time). This is a way for you to test migrate a database to the cloud and measure the performance. You might need to do some work to measure your current performance in a way that lets you determine how MI stacks up. You will also need to do some financial number crunching to decide whether there is an ROI that makes sense. If you do that, be sure you reach out to your internal finance people to understand the differences between CapEx and OpEx expenditures for your analysis. Paying $50k a year for an MI license isn't the same as spending $50k for a server and hosting.

I'm not sure what I think of MI. Like many offerings, I think there are places where it makes sense and places where it doesn't. It's not a simple decision for me as an abstract question. For specific situations, I might lean one way or the other, but I'd want to do some workload analysis to justify or discard my initial thoughts.

Share your thoughts and impressions today. You might help some of us learn more about why we might or might not use MI. You might even help clarify your own thoughts by writing them down.