Re: Fast default stuff versus pg_upgrade

Andrew Dunstan <andrew(dot)dunstan(at)2ndquadrant(dot)com> writes:
> On 06/21/2018 12:39 PM, Tom Lane wrote:
>> Andres Freund <andres(at)anarazel(dot)de> writes:
> On June 21, 2018 9:04:28 AM PDT, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> This isn't really ready to go. One clear problem is that you broke
> pg_dump'ing from any pre-v11 version, because you did not add suitable
> null outputs to the pre-v11 query variants in getTableAttrs.

> I followed the pattern used for attidentity. But why will it spit out
> warnings? It doesn't ask for the missing stuff from an older version.

Oh, I see. Well, the short answer is that that's not the style we use
in pg_dump, and the attidentity code is inappropriate/wrong too IMO.
When something has been done one way a hundred times before, thinking
you're too smart for that and you'll do it some other way does not lend
itself to code clarity or reviewability.

I might be OK with a patch that converts *all* of pg_dump's cross-version
difference handling code to depend on PQfnumber silently returning -1
rather than failing, but I don't want to see it done like that in just
one or two places.

regards, tom lane