Given the thread starter's location, it's possible that English is not his (her) first language.
DG: depends. The airlines I have worked for give their crews a DG "awareness" course, basic stuff. Classes/Divisions/labels/segregation/how to recognize a package that is DG certified (UN 4G etc etc). That's about it. And about all that's necessary.
Student: Don't make generalizations like that.... many would say, as a student, what do you know?