Re: Cursors and Transactions, why?

Eric Ridge <ebr(at)tcdi(dot)com> writes:
> wow. I should go back and read the archives to see if this was
> discussed already, but I can't help but wonder if there's a way to only
> copy pointers to the tuples. I realize VACUUM could screw it up, but
> maybe something could be invented (or re-used) to help guard against
> that.

Still looking for that free lunch, eh?

If you want to leave the tuples on-disk, then you hold a transaction
open to ensure that VACUUM won't whisk them out from under you. That's
what the normal non-HOLD cursor case will do.

If you don't want to leave the tuples on-disk, you have to copy them
someplace. You can do that with a HOLD cursor.

AFAICS any other solution will simply reinvent one or the other of these
techniques.

regards, tom lane