I am thinking that you are not using all child tables all time ,so it may
not be the best solution but if you don't want to lock your active
processes, alternatively you can try to disconnect parent-child (which is
not actively in use ) relation using no inherintence then rename old child
table .
Other tools may try to connect with different users or with same users but
using ip (not local host) and pg_hba.conf file may not allow paswordless
login except localhost.Reseting postgres password with alter user, and
configuring pg_hba.conf file can solve your problem.
Regards,
Ugur
2016-05-0