How to detect query which holds the lock in Postgres?

Question

I want to track mutual locks in postgres constantly.

I came across Locks Monitoring article and tried to run the following query:

SELECT bl.pid     A         


        

Answer 1

This modification of a_horse_with_no_name's answer will give you the blocking queries in addition to just the blocked sessions:

SELECT
    activity.pid,
    activity.usename,
    activity.query,
    blocking.pid AS blocking_id,
    blocking.query AS blocking_query
FROM pg_stat_activity AS activity
JOIN pg_stat_activity AS blocking ON blocking.pid = ANY(pg_blocking_pids(activity.pid));