[Zope-dev] deciding whether to do work in tpc_vote or tpc_finish

Hi All, I need to write a data manger that interacts with a transactional system that doesn't support two phase commit. Looking for inspiration, I went to look at zope.sqlalchemy and zope.sendmail. In the non-tpc situation, the former does the "commit" in tpc_vote while the latter does it in tpc_finish. Which is "right"? What are the tradeoffs involved? cheers, Chris