Re: long lasting select, no io nor cpu usage ?

Franck Routier <franck.routier@axege.com> writes:
> Le 20/03/2014 14:56, Tom Lane a �crit :
>> pg_locks, probably. regards, tom lane

> select * from pg_stat_activity shows 'F'alse in the waiting column for
> the query.

Hm.  The next most likely theory is that it's waiting on network I/O,
but it's hard to tell that from the outside.  Can you attach to the
stuck backend with gdb and get a stack trace?
http://wiki.postgresql.org/wiki/Generating_a_stack_trace_of_a_PostgreSQL_backend

            regards, tom lane