Re: Why we really need timelines *now* in PITR

On Mon, 2004-07-19 at 16:58, Tom Lane wrote:
> I think there's really no way around the issue: somehow we've got to
> keep some meta-history outside the $PGDATA area, if we want to do this
> in a clean fashion. We could perhaps expect the archive area to store
> it, but I'm a bit worried about the idea of overwriting the meta-history
> file in archive from time to time; it's mighty critical data and you'd
> not be happy if a crash corrupted your only copy. We could archive
> meta-history files with successively higher versioned names ... but then
> we need an API extension to get back the latest one.
>

Yes, you've convinced me.

It is critical data, but never for that long. If we only split timelines
when we recover, then we just make not to take about ~100 copies of it
immediately. If we really did recover OK, then it'll only be a few
days/weeks before we can forget it ever happened.

The crucial time is when re-running recoveries repeatedly and if we
write the manual with sufficient red ink then we'll avoid this. But
heck, not having your history file is only as bad as not having added
timelines in the first place. Not great, just more care required.

Best Regards, Simon Riggs