Will Confluence 7.3 work with SQL Server 2017 Express

[licensing]

We are looking to change our database to a a supported one for confluence 7.3.5. I see that SQL Server 2017 is supported on the supported platforms page. I am not sure if the edition matters in this case?

[Brant Schroeder]

You might be able to get it to work but it would not be supported.  Express is a light version of SQL server and has limited capabilities.  My guess is at some point it would not be able to handle your instance as it grows.

[licensing]

Is it just because of the 10 GB limitation? or are there other things that could cause problems?

[Brant Schroeder]

It is for a lot of reasons but the biggest with be around compute capacity, memory pool, cache and no sql agent present.  This will seriously limit the throughput and performance of the database.  You will also have other limitations for management of the instance that will make it difficult.    You can learn more about the differences here: https://expressdb.io/sql-server-express-feature-comparison.html#sql-2017

If you have a very small instance with very few individuals accessing it (10 or less users) then you might be ok.  If that is the case then you should just look at the free cloud addition.