Re: [PATCH] Stop ALTER SYSTEM from making bad assumptions

Stephen Frost <sfrost(at)snowman(dot)net> writes:
> * Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
>> I haven't been paying too close attention to this thread, but isn't
>> that exactly what it does now and always has? guc.c, at least, certainly
>> is going to interpret duplicate entries that way.

> The issue isn't with reading them and interpreting them, it's what
> happens when you run ALTER SYSTEM and it goes and modifies the file.
> Presently, it basically operates on the first entry it finds when
> performing a SET or a RESET.

Ah, got it. So it seems like the correct behavior might be for
ALTER SYSTEM to
(a) run through the whole file and remove any conflicting lines;
(b) append new setting at the end.

If you had some fancy setup with comments associated with entries,
you might not be pleased with that. But I can't muster a lot of
sympathy for tools putting comments in postgresql.auto.conf anyway;
it's not intended to be a human-readable file.

If anybody does complain, my first reaction would be to make ALTER
SYSTEM strip all comment lines too.

regards, tom lane