1) allow the instance to use PQO:
   parallel_max_servers  = XX
2) turn PQO off on all tables:  
   ALTER TABLE XXX PARALLEL (DEGREE 1 INSTANCES 1); or
    ALTER TABLE XXX NOPARALLEL;    
3) turn PQO on at a query by query basis with
     --+ parallel(table_alias_name, degree ,1)
   where table_alias_name is the table alias name in query
   and degree is the number representing the parallel execution degree

running into issues with update 

    ALTER TABLE cm_hour_facts NOPARALLEL;
    update /* + noparallel */  ...

still getting parallel - investigating, even ALTER SESSION ENABLE PARALLEL DML|DDL|QUERY
  
    alter session disable parallel dml;

still gets it
initial testing, this seems to turn it off

     alter session disable parallel query;

errata:
     alter session force parallel query