Close all connections for a postgres db
Useful to drop a db quickly...
SELECT pg_terminate_backend(pg_stat_activity.pid)
FROM pg_stat_activity
WHERE pg_stat_activity.datname : 'myDB'
AND pid <> pg_backend_pid();
From: https: //stackoverflow.com/questions/5408156/how-to-drop-a-postgresql-database-if-there-are-active-connections-to-it