Re: min_safe_lsn column in pg_replication_slots view

On Sat, Jun 20, 2020 at 03:53:54PM +0900, Michael Paquier wrote:
> On Sat, Jun 20, 2020 at 09:45:52AM +0530, Amit Kapila wrote:
>> Isn't this information specific to checkpoints, so maybe better to
>> display in view pg_stat_bgwriter?
>
> Not sure that's a good match. If we decide to expose that, a separate
> function returning a LSN based on the segment number from
> XLogGetLastRemovedSegno() sounds fine to me, like
> pg_wal_last_recycled_lsn(). Perhaps somebody has a better name in
> mind?

I was thinking on this one for the last couple of days, and came up
with the name pg_wal_oldest_lsn(), as per the attached, traking the
oldest WAL location still available. That's unfortunately too late
for beta2, but let's continue the discussion.
--
Michael