postgresql locked queries

sql

WITH _locks AS  (
  SELECT
    PL.pid, unnest(pg_blocking_pids(PL.pid)) AS blocking_pid
  FROM pg_locks PL
  WHERE NOT granted
)
select
  PSA.pid AS query_pid,
  LEFT(query, 200) AS query,
  CASE
    WHEN PSA.pid = L.pid THEN 'blocked' 
    WHEN PSA.pid = L.blocking_pid THEN 'blocking'
  END AS status,
  L.pid AS blocked_query_pid,
  L.blocking_pid,
  PSA.application_name,
  PSA.state AS transaction_state,
  PSA.backend_xid,
  PSA.query_start
FROM _locks L
JOIN pg_stat_activity PSA ON (
  PSA.pid = L.pid OR
  PSA.pid = L.blocking_pid
)
ORDER BY PSA.query_start;