Every so often the buildfarm shows row-ordering differences in the copy2 test, for example http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=jaguar&dt=2009-06-13%2003:00:02 ("jaguar" seems particularly prone to this for some reason, but other members have shown it too.) I believe what is happening is that autovacuum chances to trigger on the table being used, allowing some of the updated rows to be placed in positions they're not normally placed in.
There is a simple fix for that: change the table to be a temp table, thus preventing autovac from touching it. Any objections to doing that? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers