Q:

Service Packs and CUs for SQL Server, do these patches make any changes to user database files? or just instance level binaries?

I am curious about patching on SQL Server.  Does anyone know if SPs and CUs make any changes to user database files or is it just the database engine and instance level binaries that get modified/updated?
Thanks

A:

Service packs and CUs do not change user databases. What is changed is binaries and system databases. Sometimes, database that are not strictly system databases but are shipped by microsoft are changed as well via upgrade scripts (sysutility_mdw, SSISDB, distribution...)

