Re: Does psql use nested transactions?

On Tue, Aug 17, 2004 at 03:33:01PM -0300, Haroldo Stenger wrote:

Haroldo,

> On Wed, 11 Aug 2004 11:47:35 -0400, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > The other objection is that this would create very substantial overhead.
>
> why?

Establishing a savepoint is a non-trivial operation (cost-wise). Several
internal server structures have to be prepared for it. It's way cheaper than
normal transaction start and commit, but undesirable anyway if done once per
query. Worse if it's going to be seldom used.

--
Alvaro Herrera (<alvherre[(at)]dcc(dot)uchile(dot)cl>)
"La experiencia nos dice que el hombre peló millones de veces las patatas,
pero era forzoso admitir la posibilidad de que en un caso entre millones,
las patatas pelarían al hombre" (Ijon Tichy)