Re: Unstable regression test for contrib/pageinspect

Peter Geoghegan <pg(at)bowt(dot)ie> writes:
> On Sun, Nov 20, 2022 at 12:37 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> The core reloptions.sql and vacuum.sql tests are two places that are
>> also using this option, but they are applying it to temp tables,
>> which I think makes it safe (and the lack of failures, seeing that
>> they run within parallel test groups, reinforces that). Can we apply
>> that idea in pageinspect?

> I believe so. The temp table horizons guarantee isn't all that old, so
> the tests may well have been written before it was possible.

Ah, right, I see that that only dates back to v14 (cf a7212be8b).
So we can fix pageinspect's issue by making that table be temp,
but only as far back as v14.

That's probably good enough in terms of reducing the buildfarm
noise level, seeing that mamba has only reported this failure
on HEAD so far. I'd be tempted to propose back-patching
a7212be8b, but there would be ABI-stability issues, and it's
probably not worth dealing with that.

>> contrib/amcheck and contrib/pg_visibility are also using
>> DISABLE_PAGE_SKIPPING, so I wonder if they have similar hazards.

> I think that most use of DISABLE_PAGE_SKIPPING by the regression tests
> just isn't necessary.

Apparently not -- see followup discussion with Mark Dilger.

regards, tom lane