ALTER LARGE OBJECT changes the owner of a large object. Only the administrator or the owner of the to-be-modified large object can execute ALTER LARGE OBJECT.
ALTER LARGE OBJECT large_object_oid OWNER TO new_owner;
Specifies the OID of the large object to be modified.
Value range: An existing large object name.
Specifies the new owner of the object.
Value range: An existing user name/role.