Robert Haas <robertmhaas@gmail.com> writes:
> On Wed, Apr 22, 2009 at 5:44 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I think we've already milked what we can from that, since a prepared
>> xact is treated exactly like an open one with no snapshot. �The point
>> is that whatever rows it's written are still in-doubt and cannot be
>> frozen, so the wraparound horizon cannot advance past its XID.
> But surely that's not "the same" as a backend which is
> idle-in-transaction? In that case I think you still need a snapshot?
No; at least not unless it's a serializable transaction. That's the
point of the snapshot management work that Alvaro did for 8.4.
regards, tom lane
