savepoints with the same name

I was thinking thinking about the issue asked here, about an error in
a query causing the whole transaction to abort,
http://stackoverflow.com/questions/2741919/can-i-ask-postgresql-to-ignore-errors-within-a-transaction/2745677
which has already bothered so many postgresql users and has been
discussed before (it's certainly not a bug, I know).

I wonder if the suggestion I ("leonbloy") gave, of adding a SAVEPOINT
after each insert (when doing interactive work)
is reasonable.

In particular, after reading this message
http://archives.postgresql.org/pgsql-general/2009-07/msg00636.php

"If you savepoint every single insert, you'll wind up begin much
much slower..."

Does that also apply when I issue a SAVEPOINT with the same name? Does
the new savepoint release the previous and create a new
one, or does it "move" the previous? Or it's just that a new one is
created and the name "shadows" the previous, so that there are still N
active savepoints in the transaction, taking up memory/resources ?

Hernán J. González
http://hjg.com.ar/