On Fri, 2004-07-09 at 16:47, Alvaro Herrera wrote:
> On Fri, Jul 09, 2004 at 10:38:15AM -0500, Thomas Swan wrote:
>
> > visibility issue and how far do you unwind the depth of subtransactions
> > or transactions?
> >
> > BEGIN
> > UPDATE A
> > SAVEPOINT X
> > BEGIN
> > BEGIN
> > UPDATE B
> > BEGIN
> > UPDATE C
> > ROLLBACK TO SAVEPOINT X
>
> What happens here is that the user will go nuts. We will have a
> prominent entry in the docs: "using both nested transactions and
> savepoints inside a transaction can cause confusion. We recommend you
> stick to one or the other." Or something like that.
>
> (What would really happen: when ROLLBACK TO SAVEPOINT X is executed,
> nested transactions created after the SAVEPOINT will be closed.)
>
> So this is another reason why we should use COMMIT to close a nested
> transaction: it may refer to a transaction that is already closed
> because the user got confused.
Agreed.
Could we put two modes of operation in?
i.e. if you use SAVEPOINTs/ROLLBACK TO SAVEPOINT, then you're not
allowed to use nested transactions (and vice versa - so they are
mutually exclusive)...
Best Regards, Simon Riggs
