I haven't seen this mentioned anywhere (although it may have as I haven't read through the entire history of it), but would others find it useful to have ALTER SYSTEM support comments?
e.g.
ALTER SYSTEM SET autovacuum_vacuum_scale_factor = 0.01 WITH [ INLINE | HEADLINE ] COMMENT $$As most of the tables on the system are so big, we're setting this parameter lower than the default to keep bloat under more control.$$;
I just made up inline and headline to suggest that we could allow either:
autovacuum_vacuum_scale_factor = 0.01 # As most of the tables...
and
# As most of the tables on the system are so big, we're setting this parameter # lower than the default to keep bloat under more control. autovacuum_vacuum_scale_factor = 0.01
The rationale being that it's often the case one wants to document the reason for a parameter being configured so, but there's no way of doing this for settings in postgresql.auto.conf as they'll be wiped out if added manually.
