oracle sequence job

declare
job1 number;
startdate date:=to_date('2011-10-20 00:00:00','yyyy-mm-dd hh24:mi:ss');
begin
--创建序列
drop sequence seq_epcis_web_undr_opn;
create sequence seq_epcis_web_undr_opn    --创建序列名字为   a_seq
minvalue 1               --  最小值为      1
maxvalue 9999999999999999999999999999   ---  最大值

start with 1            ---   开始值       1
increment by 1
cache 100;

dbms_job.submit(job1,'P_RECALLTASK;',startdate,'startdate+1/1440');--启动任务
end;