Horton

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

Stephen Frost <sfrost@snowman.net>

View thread View on postgr.es
From: Stephen Frost <sfrost@snowman.net>
To: Ian Barwick <ian.barwick@2ndquadrant.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2019-08-03T00:13:49Z
Lists: pgsql-hackers 
Greetings,

On Fri, Aug 2, 2019 at 19:36 Ian Barwick <ian.barwick@2ndquadrant.com>
wrote:

> On 8/3/19 8:24 AM, Andres Freund wrote:
> > Hi,
> >
> > On 2019-08-03 08:22:29 +0900, Ian Barwick wrote:
> >> What I came up with shoehorned a stripped-down version of the backend
> >> config parser into fe_utils and provides a function to modify
> pg.auto.conf
> >> in much the same way ALTER SYSTEM does, but with only the basic syntax
> >> checking provided by the parser of course. And for completeness a
> >> client utility which can be called by scripts etc.
> >
> >> I can clean it up and submit it later for reference (got distracted by
> other things
> >> recently) though I don't think it's a particularly good solution due to
> the
> >> lack of actual checks for the provided GUCSs (and the implementation
> >> is ugly anyway); something like what Andres suggests below would be far
> better.
> >
> > I think my main problem with that is that it duplicates a nontrivial
> > amount of code.
>
> That is indeed part of the ugliness of the implementation.


I agree that duplicate code isn’t good- the goal would be to eliminate the
duplication by having it be common code instead of duplicated.  We have
other code that’s common to the frontend and backend and I don’t doubt that
we will have more going forward...

Thanks,

Stephen

>

Commits

  1. Doc: improve documentation about postgresql.auto.conf.

  2. Fix ALTER SYSTEM to cope with duplicate entries in postgresql.auto.conf.