PostgreSQL 11 Administration Cookbook

How to do it…

Perform the following steps:

1. Write the following query:

SELECT datname, usename, wait_event_type, wait_event, pg_blocking_pids(pid) AS blocked_by, backend_type, queryFROM pg_stat_activityWHERE wait_event_type IS NOT NULLAND wait_event_type NOT IN ('Activity', 'Client');

2. You will receive the following output:

-[ RECORD 1 ]---+-----------------datname         | postgresusename         | gianniwait_event_type | Lockwait_event      | relationblocked_by      | {18142}backend_type    | client backendquery           | select * from t;

This is, in fact, the query we described in the previous recipe, with the addition of the blocked_by column. Recall that the PID is the unique identifier assigned by the operating system to each session; for more details, see Chapter 4 ...