[Shorel]

I moved the same system from MSSQL server to Oracle, then to MySQL.

The Oracle version had a lot of logic written as SP. I migrated them to MySQL SP.

So the conclusion is: SP don't make it impossible to migrate from one database to another, and second: yes database migrations do happen.

Also: all database migrations I have known involve Oracle in one way to another. Oracle salespeople are way too nosy.