From: | Bruce Momjian <bruce(at)momjian(dot)us> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Stephen Frost <sfrost(at)snowman(dot)net>, Andrey Lepikhov <a(dot)lepikhov(at)postgrespro(dot)ru>, pgsql-hackers(at)lists(dot)postgresql(dot)org, Etsuro Fujita <etsuro(dot)fujita(at)gmail(dot)com>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> |
Subject: | Re: Ideas about a better API for postgres_fdw remote estimates |
Date: | 2020-08-31 21:47:41 |
Message-ID: | 20200831214741.GR13613@momjian.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Mon, Aug 31, 2020 at 05:46:22PM -0400, Bruce Momjian wrote:
> On Mon, Aug 31, 2020 at 01:53:01PM -0400, Tom Lane wrote:
> > Stephen Frost <sfrost(at)snowman(dot)net> writes:
> > > Feature work either requires changes to pg_dump, or not. I agree that
> > > features which don't require pg_dump changes are definitionally less
> > > work than features which do (presuming the rest of the feature is the
> > > same in both cases) but that isn't a justification to not have pg_dump
> > > support in cases where it's expected- we just don't currently expect it
> > > for statistics (which is a rather odd exception when you consider that
> > > nearly everything else that ends up in the catalog tables is included).
> >
> > > For my part, at least, I'd like to see us change that expectation, for a
> > > number of reasons:
> >
> > Yeah. I think that originally we expected that the definition of the
> > stats might change fast enough that porting them cross-version would be
> > problematic. Subsequent experience has shown that they don't actually
> > change any faster than any other aspect of the catalogs. So, while
> > I do think we must have a plan for how to cope when/if the definition
> > changes, I don't buy Bruce's argument that it's going to require more
> > maintenance effort than any other part of the system does.
>
> Well, my point is that even bucket/calculation/data text respresentation
> changes could affect dumping statistics, and that is kind of rare for
> other changes we make.
And I have been hoping someone would prove me wrong all these years, but
it hasn't happened yet. It is possible we have hit a tipping point
where the work is worth it, and I hope that is the case. I am just
explaining why I think it has not happened yet.
--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EnterpriseDB https://enterprisedb.com
The usefulness of a cup is in its emptiness, Bruce Lee
From | Date | Subject | |
---|---|---|---|
Next Message | David Rowley | 2020-08-31 21:59:05 | Re: Hybrid Hash/Nested Loop joins and caching results from subplans |
Previous Message | Bruce Momjian | 2020-08-31 21:46:22 | Re: Ideas about a better API for postgres_fdw remote estimates |