Date: Thu, 15 Sep 2022 00:01:00 +0200
From: Sandro Santilli <strk@kbt.io>
Sender: strk@kbt.io
To: pgsql-hackers@postgresql.org
Cc: Laurenz Albe <laurenz.albe@cybertec.at>, Regina Obe <lr@pcorp.us>,
	Tom Lane <tgl@sss.pgh.pa.us>
Subject: Re: [PATCH] Support % wildcard in extension upgrade filenames
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	pgsql-hackers@postgresql.org,
	Laurenz Albe <laurenz.albe@cybertec.at>, Regina Obe <lr@pcorp.us>,
	Tom Lane <tgl@sss.pgh.pa.us>
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I'm attaching an updated version of the patch. This time the patch
is tested. Nothing changes unless the .control file for the subject
extension doesn't have a "wildcard_upgrades = true" statement.

When wildcard upgrades are enabled, a file with a "%" symbol as
the "source" part of the upgrade path will match any version and
will be used if a specific version upgrade does not exist.
This means that in presence of the following files:

    postgis--3.0.0--3.2.0.sql
    postgis--%--3.2.0.sql

The first one will be used for going from 3.0.0 to 3.2.0.

This is the intention. The patch lacks automated tests and can
probably be improved.

For more context, a previous (non-working) version of this patch was
submitted to commitfest: https://commitfest.postgresql.org/38/3654/

--strk;

On Sat, Jun 04, 2022 at 11:20:55AM +0200, Sandro Santilli wrote:
> On Sat, May 28, 2022 at 04:50:20PM +0200, Laurenz Albe wrote:
> > On Fri, 2022-05-27 at 17:37 -0400, Regina Obe wrote:
> > >
> > > https://lists.osgeo.org/pipermail/postgis-devel/2022-February/029500.html
> > > 
> > > Does anyone think this is such a horrible idea that we should abandon all
> > > hope?
> > 
> > I don't think this idea is fundamentally wrong, but I have two worries:
> > 
> > 1. It would be a good idea good to make sure that there is not both
> >    "extension--%--2.0.sql" and "extension--1.0--2.0.sql" present.
> >    Otherwise the behavior might be indeterministic.
> 
> I'd make sure to use extension--1.0--2.0.sql in that case (more
> specific first).
> 
> > 2. What if you have a "postgis--%--3.3.sql", and somebody tries to upgrade
> >    their PostGIS 1.1 installation with it?  Would that work?
> 
> For PostGIS in particular it will NOT work as the PostGIS upgrade
> script checks for the older version and decides if the upgrade is
> valid or not. This is the same upgrade code used for non-extension
> installs.
> 
> >    Having a lower bound for a matching version might be a good idea,
> >    although I have no idea how to do that.
> 
> I was thinking of a broader pattern matching support, like:
> 
>   postgis--3.%--3.3.sql
> 
> But it would be better to start simple and eventually if needed
> increase the complexity ?
> 
> Another option could be specifying something in the control file,
> which would also probably be a good idea to still allow some
> extensions to use '%' in the version string (for example).
> 
> --strk; 
> 
>   Libre GIS consultant/developer
>   https://strk.kbt.io/services.html
> 
>