Heikki Linnakangas <heikki@enterprisedb.com> writes:
> We could just allow any value up to 1.0, and note in the docs that you
> should leave some headroom, unless you don't mind starting the next
> checkpoint a bit late. That actually sounds pretty good.
Yeah, that sounds fine. There isn't actually any harm in starting a
checkpoint later than otherwise expected, is there? The worst
consequence I can think of is a backend having to take time to
manufacture a new xlog segment, because we didn't finish a checkpoint
in time to recycle old ones. This might be better handled by allowing
a bit more slop in the number of recycled-into-the-future xlog segments.
Come to think of it, shouldn't we be allowing some extra slop in the
number of future segments to account for xlog archiving delays, when
that's enabled?
regards, tom lane