Today I realized that I had a clustered instance of a SQL Server 2008 R2, which was installed as a Standard edition.
The databases which were about to be moved to that instance were residing on a Enterprise edition test environment, and I know for a fact that they were utilizing some of the Enterprise features.
By the way, if you are wondering if your database is using any enterprise features, you can run the following query:
SELECT * FROM sys.dm_db_persisted_sku_features;
So why is this important? It is important because if you are to migrate a database from Enterprise to Standard edition, you will be able to do it only if the database is not using any Enterprise features.
So, back to the topic: what do I do with an instance with Standard edition which should have been installed as Enterprise? Do I have to uninstall and reinstall everything over again?
No! No re-installation needed.
It is simple: insert the installation media for SQL Server Enterprise edition (or use a share, or a mounted image file), and double-click the start.exe file, as you would during a regular installation. When the installation wizard starts, go to Management tab and at the top you will see ‘Edition upgrade’. Click on it, and from then on it is simple. Just make sure to select the right instance which should be upgraded (if you have more than one instance on the machine).
And, if you are curious to know how easy it is to do the opposite: downgrade the Enterprise edition to a Standard… well, you will have to uninstall and reinstall.
Here is a useful link with the path of version and edition upgrade.