Re: Extracting cross-version-upgrade knowledge from buildfarm client

Andrew Dunstan <andrew@dunslane.net> writes:
> fairwren and drongo are clean except for fairywren upgrading 9.6 to 11.
> This appears to be a longstanding issue that the fuzz processing was
> causing us to ignore. See for example
>
<https://buildfarm.postgresql.org/cgi-bin/show_stage_log.pl?nm=fairywren&dt=2022-09-01%2018%3A27%3A28&stg=xversion-upgrade-REL_10_STABLE-REL_11_STABLE>

Interesting.  I suspected that removing the fuzz allowance would teach
us some things we hadn't known about.

> I propose to add this to just the release 11 AdjustUpgrade.pm:
>     # float4 values in this table on Msys can have precision differences
>     # in representation between old and new versions
>     if ($old_version < 10 && $dbnames{contrib_regression_btree_gist} &&
>         $^O eq 'msys')
>     {
>         _add_st($result, 'contrib_regression_btree_gist',
>                 'drop table if exists float4tmp');
>     }

Seems reasonable (but I wonder if you don't need "$old_version < 11").
A nicer answer would be to apply --extra-float-digits=0 across the
board, but pre-v12 pg_dump lacks that switch.

            regards, tom lane