Re: pg_dump versus rules, once again

On 17 November 2016 at 03:45, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Wed, Nov 16, 2016 at 10:14 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> >> On Wed, Nov 16, 2016 at 10:00 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >>> The changes in pg_backup_archiver.c would have to be back-patched
> >>> into all versions supporting --if-exists, so that they don't fail
> >>> on dump archives produced by patched versions.
> >
> >> Even if you patch future minor releases, past minor releases are still
> >> going to exist out there in the wild for a long, long time.
> >
> > Yeah, but it would only matter if you try to use pg_restore --clean
> --if-exists
> > with an archive file that happens to contain a view that has this issue.
> > Such cases would previously have failed anyway, because of precisely
> > the bug at issue ... and there aren't very many of them, or we'd have
> > noticed the problem before. So I don't feel *too* bad about this,
> > I just want to make sure we have a solution available.
>
> Right, OK.
>

For what it is worth we just run into this problem on our postgres 9.2.17
installation on a hunch we (after reading Tom's initial email replaced the
view that caused this by this

create view ... as select * from (...original view definition...)
hack_around_pg_dump_versus_rules_bug;

Which caused pg_dump to change its behavior and instead emit create view
.... which is what we wanted (because we take filtered down and dependency
ordered outputs of pg_dump as the starting point for new patches to the
db). But it surprised me mildly that the hack "worked" so I thought I
would mention it here. It might just mean that I'm misunderstanding the
bug but if there was really a dependency in the original that dependency
still exists now.

> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>
>
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