1.direct+parallel
alter session enable parallel dml;
insert /*+ append parallel(XXXX,default)*/ into XXXX select * from YYYY;

2.direct+parallel
create table XXXX parallel as select * from YYYY;

3.direct+parallel
alter session force parallel dml;
alter session force parallel ddl;
create table XXXX as select * from YYYY;

4.direct
create table XXXX as select * from YYYY;