FYI, I test pg_upgrade by loading the old cluster's regression database
from a pg_dump output file, then after the upgrade, I dump the
regression database of the new cluster and diff the changes.
The problem I just encountered is that pg_dump uses
extra_float_digits=-3 for 9.0, while previous releases used '2'. I had
to do hack each server version to get a dump output that would match
without rounding errors --- it did eventually work and validated.
-- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB
http://enterprisedb.com