On Fri, 26 Oct 2007, Andrew Sullivan wrote:
> Sort of a filthy hack, but what about always having an _extra_
> segment around? The bgwriter could do that, no?
Now it could. The bgwriter in <=8.2 stops executing when there's a
checkpoint going on, and needing more WAL segments because a checkpoint is
taking too long is one of the major failure cases where proactively
creating additional segments would be most helpful.
The 8.3 bgwriter keeps running even during checkpoints, so it's feasible
to add such a feature now. But that only became true well into the 8.3
feature freeze, after some changes Heikki made just before the "load
distributed checkpoint" patch was commited. Before that, it was hard to
implement this feature; afterwards, it was too late to fit the change into
the 8.3 release. Should be easy enough to add to 8.4 one day.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD