Hey all, According to http://www.postgresql.org/docs/9.2/static/sql-alterrole.html
A query: ALTER ROLE davide WITH PASSWORD NULL; removes a role's password. But it's impossible to pass empty (NULL) password to the backend by using libpq, because connectOptions2() defined the fe-connect.c reads a password from the ~/.pgpass even when a password specified as an empty string literal (""). Also, when connecting to the server via psql(1) by using a role with removed password psql exists with status 2 and prints the error message: psql: fe_sendauth: no password supplied Thanks. -- // Dmitriy.