--Find the PID by running this sql: SELECT pid , query, * from pg_stat_activity WHERE state != 'idle' ORDER BY xact_start; --You'll find the pid in the first (left) column, and the first (top) row is likely to be the query you'd like to terminate. --I'll assume the pid is 1234 below. --You may cancel a query through SQL (i.e. without shell access) as long as it's yours or you have super user access: select pg_cancel_backend(1960); --This is the "soft" way ... the query won't disappear immediately. If you're in a hurry, try this one instead: select pg_terminate_backend(1960); --If you have shell access and root or postgres permissions you can also do it from the shell: kill -INT 1234 --If that doesn't help, use: kill 1234