postgres_locks_blocked.sql

--
--  Author: Hari Sekhon
--  Date: 2020-08-05 18:16:55 +0100 (Wed, 05 Aug 2020)
--
--  vim:ts=4:sts=4:sw=4:et:filetype=sql
--
--  https://github.com/HariSekhon/SQL-scripts
--
--  License: see accompanying Hari Sekhon LICENSE file
--
--  If you're using my code you're welcome to connect with me on LinkedIn and optionally send me feedback to help steer this or other code I publish
--
--  https://www.linkedin.com/in/HariSekhon
--

-- List PostgreSQL locks blocked
--
-- Requires PostgreSQL 9.2+
--
-- Tested on PostgreSQL 9.2+, 10.x, 11.x, 12.x, 13.0

-- https://wiki.postgresql.org/wiki/Lock_Monitoring

SELECT
    blocked_locks.pid         AS blocked_pid,
    blocked_activity.usename  AS blocked_user,
    blocking_locks.pid        AS blocking_pid,
    blocking_activity.usename AS blocking_user,
    blocked_activity.query    AS blocked_statement,
    blocking_activity.query   AS current_statement_in_blocking_process
FROM
    pg_catalog.pg_locks AS blocked_locks
JOIN
    pg_catalog.pg_stat_activity AS blocked_activity
ON
    blocked_activity.pid = blocked_locks.pid
JOIN
    pg_catalog.pg_locks AS blocking_locks
ON
    blocking_locks.locktype = blocked_locks.locktype
    AND blocking_locks.database       IS NOT DISTINCT FROM blocked_locks.database
    AND blocking_locks.relation       IS NOT DISTINCT FROM blocked_locks.relation
    AND blocking_locks.page           IS NOT DISTINCT FROM blocked_locks.page
    AND blocking_locks.tuple          IS NOT DISTINCT FROM blocked_locks.tuple
    AND blocking_locks.virtualxid     IS NOT DISTINCT FROM blocked_locks.virtualxid
    AND blocking_locks.transactionid  IS NOT DISTINCT FROM blocked_locks.transactionid
    AND blocking_locks.classid        IS NOT DISTINCT FROM blocked_locks.classid
    AND blocking_locks.objid          IS NOT DISTINCT FROM blocked_locks.objid
    AND blocking_locks.objsubid       IS NOT DISTINCT FROM blocked_locks.objsubid
    AND blocking_locks.pid != blocked_locks.pid
JOIN
    pg_catalog.pg_stat_activity blocking_activity
ON
    blocking_activity.pid = blocking_locks.pid
WHERE
    NOT blocked_locks.granted;