pg_dumpall: query failed:

gnotari@linkgroup.it writes:

I have this problem with a nightly script that dumps the db:
pg_dumpall: query failed: ERROR: Unable to convert abstime 'invalid' to
timestamp
pg_dumpall: query was: SELECT usename, usesysid, passwd, usecreatedb,
usesuper, CAST(valuntil AS timestamp) FROM pg_shadow WHERE usesysid <>
(SELECT datdba FROM pg_database WHERE datname = 'template0');

Hm, I'm surprised no one has complained of this before. I guess it's
not common to put 'invalid' into pg_shadow.valuntil.

The cast to timestamp is really unnecessary, so I've fixed the problem
for 7.4 by taking it out. You could do the same to your copy of
pg_dumpall.c, or you could change the pg_shadow entry to be NULL rather
than 'invalid'.

regards, tom lane