Re: Writing WAL files

> I suggest that in PG12 you can monitor the
>> "lag" of a standby server more directly by looking at columns write_lag,
>> flush_lag, replay_lag in the pg_stat_replication view.
>
>
> And are those things updated when there are no changes to the master
> database?
> If so, can anyone make the case that continually checking and updating
> them (how often?) wastes fewer electrons than shipping an empty file every
> few minutes?
>
> Or are they only measured when something is updated?
>

If you setup a scripted process to update a single row with a timestamptz
on the source/primary every minute, then you have a very simple consistent
change and also a way to check on the replica what is current time vs
last_scripted_update_time if you will and know the approx lag. It would
seem like a simple albeit hacky solution to you wanting a file every X
minutes regardless of server activity.

By the by, top-posting (reply above all quoted text) is discouraged on
these groups.