Show info on postgres locks

pg_locks.sql

SELECT bl.pid                 AS blocked_pid,
       a.usename              AS blocked_user,
       ka.query               AS current_statement_in_blocking_process,
       now() - ka.query_start AS blocking_duration,
       kl.pid                 AS blocking_pid,
       ka.usename             AS blocking_user,
       a.query                AS blocked_statement,
       now() - a.query_start  AS blocked_duration
FROM  pg_catalog.pg_locks         bl
 JOIN pg_catalog.pg_stat_activity a  ON a.pid = bl.pid
 JOIN pg_catalog.pg_locks         kl ON kl.transactionid = bl.transactionid AND kl.pid != bl.pid
 JOIN pg_catalog.pg_stat_activity ka ON ka.pid = kl.pid
WHERE NOT bl.GRANTED;