Truncate table hanging with no other running queries

Here's a few stock queries I use to investigate

select t.relname,pid,mode,granted
from pg_locks l, pg_stat_all_tables t
where l.relation=t.relid order by relation asc;

select distinct(relation) table_id
,xid
,pid
,txn_start
,lock_mode
,trim(nspname) schema_name
,trim(relname) table_name
from svv_transactions
left join pg_class on pg_class.oid = svv_transactions.relation
join pg_namespace on pg_namespace.oid = relnamespace;

You can also use stv_locks;