Simon Riggs wrote:
> On Tue, 2010-04-20 at 21:03 -0400, Tom Lane wrote:
>> Simon Riggs <simon@2ndQuadrant.com> writes:
>>> Following patch writes a new WAL record that just says "copy foo to
>>> newts" and during replay we flush buffers and then re-execute the copy
>>> (but only when InArchiveRecovery). So the copy happens locally on the
>>> standby, not copying from primary to standby. We do this just with a
>>> little refactoring and a simple new WAL message.
>> And what happens to crash-recovery replay? You can't have it both ways,
>> either the data is in WAL or it's missing.
>
> The patch changes nothing in the case of crash recovery.
What happens if the record is replayed twice in archive recovery? For
example if you stop and restart a standby server after it has replayed
that record. What does the 2nd redo attempt do if the source file was
already deleted by the 1st recovery.
I also think we shouldn't be fiddling with this at this stage in the
release cycle.
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com