How can I establish whether it would be a good idea to upgrade from Express to Standard?
I am trying to work out whether it would be better to delete records or upgrade.


This is a business decision, not a technical one. Do not just delete data "to make space" - if the data is important and must be retained, then the organization will have to find a way to pay to keep it around.

You can't downgrade SQL Server in the way you're suggesting.

If you want to explore the possibility of upgrading to a paid edition of SQL Server, I suggest setting up a new server with Developer Edition installed (Developer Edition is free). Then take a backup of your current database, restore it to this test server, and run a sample of your workload against that.

If you decide you need to upgrade to Standard Edition, this method (backup &amp; restore) is also how you'll move your data over. I do not recommend performing an in-place upgrade (which is what your proposed method suggests).

If you're currently satisfied with the overall performance of your setup, and only looking into upgrading due to the database size limitations of Express Edition, you have a few options:


Create a second database which mirrors the first, splitting the data between the two. This will require application changes
Move "old" data to a second (archival) database based on age, deleting it from the original database
Just delete the old data altogether
Implement page- or row-level compression on your tables &amp; indexes to buy some more time. But eventually, you'll hit the 10GB limit anyway.
Migrate to a cloud-hosted database platform like Azure SQL DB where you'll pay for what you use


Options 2 &amp; 3 should only be considered if the business requirements for the data allow for it. Option 5 should only be considered if the business's data governance policies allow for it.