When GP says 'you can use the advanced features', 'you' refers to the person developing the ORM, not to a developer using the ORM. So the ORM author can do the

When GP says 'you can use the advanced features', 'you' refers to the person developing the ORM, not to a developer using the ORM. So the ORM author can do the hard work of allowing advanced features to work across databases. And it's transparent to the developer using the ORM.