"Greg Stark" <[EMAIL PROTECTED]> writes: > On Wed, Oct 1, 2008 at 2:54 PM, Tom Lane <[EMAIL PROTECTED]> wrote: >> So it seems like the appropriate generalization is to have an array of >> read positions inside the tuplestore and allow callers to say "read >> using position N", plus some API to allow positions to be allocated to >> different requestors.
> One other reason the tuplestore should know the position of all the > readers is that ideally it would want to be able to discard any tuples > older than the oldest read position. That also means it needs to know > when all the call sites have allocated their position and don't need > to reset it. Good point. So we'd need per-position capability flags, not per-tuplestore. I hadn't realized that this would be relevant to window functions. Now that I know that, I propose fixing tuplestore for multiple positions and committing it separately, before I go back to the CTE patch. Then Hitoshi-san will have something he can work with too. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers