Robert Haas <robertmhaas@gmail.com> writes:
> On the other hand, if we simply say "PostgreSQL computes the
> replication delay by subtracting the time at which the WAL was
> generated, as recorded on the master, from the time at which it is
> replayed by the slave" then, hey, we still have a wart, but it's
> pretty clear what the wart is and how to fix it, and we can easily
> document that. Again, if we could get rid of the failure modes and
> make this really water-tight, I think I'd be in favor of that, but it
> seems to me that we are in the process of expending a lot of energy
> and an even larger amount of calendar time to create a system that
> will misbehave in numerous subtle ways instead of one straightforward
> one. I don't see that as a good trade.
Well, okay, but let's document "if you use this feature, it's incumbent
on you to make sure the master and slave clocks are synced. We
recommend running NTP." or words to that effect.
regards, tom lane