When doing a 7 -> 7.5 update I had some issues. Executing "update-epidatabase" in the package manager console showed me the following error message:
System.Data.SqlClient.SqlException (0x80131904): Incorrect syntax near 'MERGE'. You may need to set the compatibility level of the current database to a higher value to enable this feature. See help for the SET COMPATIBILITY_LEVEL option of ALTER DATABASE.
So I tried changing the compability level of the database from SQL Server 2000 (yeah, the database is pretty old) to 2008, and the update script executed successfully.
However - I'm wondering if this may have some unwanted side-effects that I should be aware of when I do this in our live environment?
I believe there is no side effect for this, if you have no plan to access your database from old SQL Server version. Indeed, it should not be related to EPiServer at all, only the MERGE keyword exposed the issue:
There is no plan accessing the db from older SQL Server versions, so I guess we're good. Thank you.