Re: Nested transactions: low level stuff

Bruce Momjian wrote:
> 
> Hiroshi Inoue wrote:
> > Tom Lane wrote:
> > >
> > > Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> > > > Sorry I have a basic question.
> > > > Was there any consensus we would introduce nested transactions
> > > > (or savepoints) in the way currently discussed ?
> > >
> > > I think we are a long way from saying we can or will actually do it.
> > > Error handling and resource management (eg locks) are a couple of other
> > > huge cans of worms that have yet to be opened.  But certainly a solid
> > > design for the transaction logging and tuple validity checking is a
> > > necessary step.
> >
> > Is the way to undo data rejected already ?
> 
> You mean abort subtransactions?  Each subtransaction gets its own
> transaction id, so we just mark that as aborted --- there is no undo of
> tuples, though I had originally suggested that approach years ago.

Vadim planned to implement the savepoints functionality
using UNDO mechanism. AFAIR it was never denied explicitly.

regards,
Hiroshi Inouehttp://www.geocities.jp/inocchichichi/psqlodbc/