定时任务每隔一秒插入一条数据，结果每隔5秒插入一条数据，请教是什么原因

create or replace procedure proc_alarmsASteim date;BEGINteim := sysdate;insert into alarms(alarms.alarm_status,alarms.alarm_datetime) values(0,teim);commit;end proc_alarms;

begin  sys.dbms_job.submit(job => :job,                      what => 'proc_alarms;',                      next_date => to_date('22-09-2011 14:37:09', 'dd-mm-yyyy hh24:mi:ss'),                      interval => 'sysdate+1/24/3600');  commit;end;