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

* Robert Haas (robertmhaas@gmail.com) wrote:
> On Sat, Jun 22, 2019 at 5:13 PM Stephen Frost <sfrost@snowman.net> wrote:
> > All that said, whatever code it is that we write for pg_basebackup to do this properly should go into our client side library, so other tools can leverage that and avoid having to write it themselves.
> 
> That is probably only going to help people who are writing in C (or
> maybe some close family member) and a lot of tools for managing
> PostgreSQL will be written in scripting languages.  It is unlikely
> that those people are going to get all of the rules for parsing a file
> full of GUC settings exactly right, because translating flex into
> Python is probably not anybody's idea of a fun time. So you'll end up
> with a bunch of rewrite-postgresql.auto.conf tools written in
> different languages at varying degrees of quality many of which will
> misfire in corner cases where the GUC names contain funny characters
> or the whitespace is off or there's unusual quoting involved.

Calling into C functions from Python certainly isn't new, nor is it
difficult to do from Perl, or various other languages, someone just
needs to write the bindings.  I'm not sure where the idea came from that
someone would translate flex into Python, that's certainly not what I
was suggesting at any point in this discussion.

> If you just decreed that it was OK to append to the file, you could
> avoid all that.

As I said elsewhere on this thread, I have absolutely no problem with
that as the documented approach to working with this file- but if that's
what we're going to have be the documented approach, then everything
should be using that approach...

Thanks,

Stephen