Re: pgsql: doc: Further clarify how recovery target parameters are applied

On Wed, Nov 6, 2019 at 4:29 PM Peter Eisentraut
<peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
>
> On 2019-11-06 05:48, Fujii Masao wrote:
> > Patch attached. As I argued upthread, IMO it's better to remove
> > the latter description from the doc and the patch does that.
> > Also the patch adds "mainly" into the former description.
>
> I think we should list explicitly what is applied and what is not. This
> is the reference documentation after all.

That's possible, but may make the document more complicated and confusing,
I'm afraid. Because the parameters used for archive recovery and standby mode
are not categorized cleanly. For example,

- Parameters from Section 19.6.1. "Sending Servers" will be used except
track_commit_timestamp (in standby mode) and except track_commit_timestamp
and wal_init_zero (in archive recovery)
- Parameters from Section 19.6.3. "Standby Servers" will be used in standby
mode, but will not used except hot_standby, recovery_min_apply_delay, etc
in archive recovery.
- Parameters from Section 19.5.3. "Archiving" will be used in both standby mode
and archive recovery, but except archive_timeout.

So we would need to list such several parameters like the above
and which might make the document more complicated. Also which would
make the maintenance of the document harder.

Or it might be better to add something like "This setting has no effect if
in standby mode / archive recovery" into the description of each parameter,
instead.

Regards,

--
Fujii Masao