Find active queries in PostgreSQL

SELECT pid, state, now() - query_start AS duration, left(query, 80) AS query
FROM pg_stat_activity
WHERE state != 'idle' AND usename = 'myuser'
ORDER BY query_start;

Example output:

   pid   | state  |    duration     |                                    query
---------+--------+-----------------+------------------------------------------------------------------------------
 1648516 | active | 01:29:28.979693 |                                                                             +
         |        |                 | UPDATE myschema.mytable1 eeu                                   +
         |        |                 | SET aggregated_value = (SELECT e.aggregated_value FROM

This is the query I am looking for, started in another session. The full query text is

UPDATE myschema.mytable1 eeu
SET aggregated_value = (SELECT e.aggregated_value FROM myschema.mytable2 e WHERE e.systemid = eeu.entitet AND e.instansid = eeu.instansid);