Обсуждение: intermittent FD regression check failure

The sort of failure shown below has happened a few times recently. See 
recent failures on crake, mastodon and casteroides at 
<http://www.pgbuildfarm.org/cgi-bin/show_failures.pl>. It seems harmless 
enough. Do we need an alternative regression results file, or is there 
some way to prevent this?

cheers

andrew
   *** /home/bf/bfr/root/HEAD/pgsql.4238/../pgsql/src/test/regress/expected/foreign_data.out    Fri Apr  1 11:37:02
2011  --- /home/bf/bfr/root/HEAD/pgsql.4238/src/test/regress/results/foreign_data.out    Mon Apr 25 09:41:48 2011
***************  *** 1088,1098 ****      DROP USER MAPPING FOR regress_test_role SERVER s6;      DROP FOREIGN DATA
WRAPPERfoo CASCADE;      NOTICE:  drop cascades to 5 other objects   ! DETAIL:  drop cascades to server s4      drop
cascadesto user mapping for foreign_data_user      drop cascades to server s6   - drop cascades to server s9   - drop
cascadesto user mapping for unprivileged_role      DROP SERVER s8 CASCADE;      NOTICE:  drop cascades to 2 other
objects     DETAIL:  drop cascades to user mapping for foreign_data_user   --- 1088,1098 ----      DROP USER MAPPING
FORregress_test_role SERVER s6;      DROP FOREIGN DATA WRAPPER foo CASCADE;      NOTICE:  drop cascades to 5 other
objects  ! DETAIL:  drop cascades to server s9   ! drop cascades to user mapping for unprivileged_role   ! drop
cascadesto server s4      drop cascades to user mapping for foreign_data_user      drop cascades to server s6      DROP
SERVERs8 CASCADE;      NOTICE:  drop cascades to 2 other objects      DETAIL:  drop cascades to user mapping for
foreign_data_user

Andrew Dunstan <andrew@dunslane.net> writes:
> The sort of failure shown below has happened a few times recently. See 
> recent failures on crake, mastodon and casteroides at 
> <http://www.pgbuildfarm.org/cgi-bin/show_failures.pl>. It seems harmless 
> enough. Do we need an alternative regression results file, or is there 
> some way to prevent this?

There's no real guarantee about the order in which dependency.c lists
the dependencies (it's going to depend on the order in which the rows
happen to be stored in pg_depend).  There are some other regression
tests that cope with this by temporarily doing \set VERBOSITY terse
--- if the failures bug you, I'd suggest that, not trying to make an
alternate expected file for every order observed in the field.
        regards, tom lane