{パラレル実行}パラレルDMLを有効化

https://docs.oracle.com/cd/F19136_01/vldbg/types-parallelism.html#GUID-5EB01FA8-030B-45BB-9B16-2D13881F6010

alter session enable parallel dml ;

alter session enable parallel ddl ;
alter session enable parallel query ;

alter session force parallel dml parallel 2;

alter session force parallel ddl parallel 2;
alter session force parallel query parallel 2;