Re: Odd 9.4, 9.3 buildfarm failure on s390x

On 10/01/2018 12:50 PM, Tom Lane wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
>> On 2018-10-01 12:13:57 -0400, Tom Lane wrote:
>>> Yeah. So our choices are
>>>
>>> (1) Retain the current restriction on what sort comparators can
>>> produce. Find all the places where memcmp's result is returned
>>> directly, and fix them. (I wonder if strcmp has same issue.)
>>>
>>> (2) Drop the restriction. This'd require at least changing the
>>> DESC correction, and maybe other things. I'm not sure what the
>>> odds would be of finding everyplace we need to check.
>>>
>>> Neither one is sounding very pleasant, or maintainable.
>> (2) seems more maintainable to me (or perhaps less unmaintainable). It's
>> infrastructure, rather than every datatype + support out there...
> I guess we could set up some testing infrastructure: hack int4cmp
> and/or a couple other popular comparators so that they *always*
> return INT_MIN, 0, or INT_MAX, and then see what falls over.
>
> I'm fairly sure that btree, as well as the sort code proper,
> has got an issue here.
>
>

I agree option 2 seems less unmaintainable. (Nice use of litotes there?)

cheers

andrew

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Andrew Dunstan https://www.2ndQuadrant.com
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