PostgreSQL: see the age of locks

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

select a.pid, c.relname, l.transactionid, l.mode, l.granted, a.usename, a.query, a.query_start, age(now(), a.query_start) as "age" from pg_stat_activity a join pg_locks l on l.pid = a.pid join pg_class c on c.oid = l.relation order by a.query_start