In my case it is required to change owner for schema in PostgreSQL database, I used statement:
ALTER SCHEMA schema_name OWNER TO role_name
but the statement is running and running and running... During the day re-started it at least twice after more than 3 hours running time.
Looks like something is locked and it is preventing statement finishing. However after several queries to pg_locks/pg_class/pg_namespace I didnt find anything that would be a reason for the lock.
Please, share you expirience how to manage/investigate such cases.
For now the case is resolved : once one of my collegue switched off his PC then my statement finished successfully.