Andreas <maps(dot)on(at)gmx(dot)net> writes:
> As far as I know, PG handles 1 transaction per connection an several
> savepoints boxed within.
One transaction *at a time*, not one for the whole life of the session.
A good general design rule is that no transaction should stay open for
very long: do what you need to do and commit. So the scenarios you're
envisioning are not relevant to a well-designed application.
regards, tom lane