POS

[BRIAN SPILSBURY]

MD> Ok, I was trying to come up with a way to do fine-grain object-level
MD> persistence; maybe there is a more efficient way to do than to wrap
MD> all mutations of the system.

I suspect that you'll have to look to the existing systems which are
designed with that in mind, and then look at the functional requirements
to implement 'em.

Firstly we need a commit to only return when the transaction is down
on persistent media - ie your HD.

Hmm, I can't think of a secondly off the top of my head.

So if we can define an allocation space which is necessarily in
sync with its associated HD space, and we can tell objects to get allocated
in one of these spaces, then I think we have the pre-requisite for
implementing a traditional fine-grain object-level persistence with
transactions.

There may be more efficient ways to guarantee transactions are robust
and persistent, but I can't think of any which are fundamentally
different to the persistent transactional db model ":(

Brian