并行执行

1、显示并行设置参数

show parameter parallel;

2、创建表

create table t parallel 4 as select * from dba_objects;

3、查看并行执行计划

alter session enable parallel dml;

 explain plan for delete /*+ parallel(t 2) */ from t;

select * from table(dbms_xplan.display); 

4、并行执行inset into

insert /*+parallel(t1,4) */into t select /* paraller(t,4) */ id,name from t1

5、PCWP和PCWC 

parallel combined with parent （child）