Sorry I can't help you here. All I can tell you is that my colleague has used setVector / getVector (not setDataBuffer) and SQL collection types (not PLSQL collection types defined inside packages) and he was able to do what you want. Too bad setDataBuffer does not seem to work with SQL Nested Tables (my test failed, but you can check by yourself and maybe ask support).

Do not hesitate if you have other questions.

Good luck & Regards,

rbaraer