dbms_job vs Oracle Scheduler

      在oracle 10g之前，我们常使用DBMS_JOB提供的相关软件包来管理oracle数据库中的定时任务，虽然10g之后，更多推荐功能更强大的DBMS_SCHEDULER，但由于习惯问题，很多时候还是会用到DBMS_JOB，下面简单介绍下两种工作的用法。

DBMS_JOB

1，参数JOB_QUEUE_PROCESSES
    oracle已job queue队列的形式管理定时任务，因此需要先设置JOB_QUEUE_PROCESSES参数为非0的数值，一般10即可
    ALTER SYSTEM SET JOB_QUEUE_PROCESSES = 10 scope=both;
2, DBMS_JOB用法及例子

SUBMIT：提交任务到队列

VARIABLE jobno NUMBER
BEGIN
   DBMS_JOB.SUBMIT(:jobno,
      'DBMS_DDL.ANALYZE_OBJECT(''TABLE'',''SYS'', ''TEST'',''ESTIMATE'', NULL, 50);',
      SYSDATE, 'SYSDATE + 1');
   COMMIT;
END;
/
sys@MS4ADB3(dtydb5)> PRINT jobno

     JOBNO
----------
         1

查看任务执行情况

sys@MS4ADB3(dtydb5)> select job,what,NEXT_DATE from dba_jobs;

       JOB WHAT                                                                                                 NEXT_DATE
---------- ---------------------------------------------------------------------------------------------------- -------------------
         1 DBMS_DDL.ANALYZE_OBJECT('TABLE','SYS', 'TEST','ESTIMATE', NULL, 50);                                 2014-04-01 14:16:53

有效job的描述例子如下

'myproc(''10-JAN-99'', next_date, broken);'
'scott.emppackage.give_raise(''JFEE'', 3000.00);'
'dbms_job.remove(job);'

常用的job时间间隔

'SYSDATE + 7'
每隔7天

'SYSDATE + 1/48'
每半个小时

'NEXT_DAY(TRUNC(SYSDATE), ''MONDAY'') + 15/24'
每周一下午三点

'NEXT_DAY(ADD_MONTHS(TRUNC(SYSDATE, ''Q''), 3), ''THURSDAY'')'
每季度的第一个周四

REMOVE
从队列中删除

BEGIN
DBMS_JOB.REMOVE(14144);
END;
/

CHANGE
修改任务的属性

BEGIN
DBMS_JOB.CHANGE(14144, NULL, NULL, 'SYSDATE + 3');
END;
/

WHAT
修改任务的描述    

BEGIN
DBMS_JOB.WHAT(1,
      'DBMS_DDL.ANALYZE_OBJECT(''TABLE'',''SYS'', ''T2'',''ESTIMATE'', NULL, 50);');
END;
/

NEXT_DATE
任务下一次执行的时间

BEGIN
DBMS_JOB.NEXT_DATE(14144, SYSDATE + 4);
END;
/

INTERVAL
任务执行的时间间隔
    
BROKEN
终止任务的执行

RUN
运行任务    

BEGIN
DBMS_JOB.RUN(1);
END;
/

查看job的相关信息，可以查看视图DBA_JOBS和DBA_JOBS_RUNNING

sys@MS4ADB3(dtydb5)> SELECT JOB, NEXT_DATE, NEXT_SEC, FAILURES, BROKEN
  2     FROM DBA_JOBS;

       JOB NEXT_DATE           NEXT_SEC                                                           FAILURES BR
---------- ------------------- ---------------------------------------------------------------- ---------- --
         1 2014-04-01 14:39:39 14:39:39                                                                  0 N    

    
例外，jobs运行失败的日志在alert log里面。

DBMS_SCHEDULER

DBMS_SCHEDULER功能更强大，具有如下优点

    Logging of job runs (job history) -- job运行的日志
    Simple but powerful scheduling syntax (similar to but more powerful than cron syntax) -- 更简单强大的语法
    Running of jobs outside of the database on the operating system (see below)-- 运行os命令
    Resource management between different classes of jobs-- 资源管理功能
    Use of job arguments including passing of objects into stored procedures-- 使用任务参数
    Privilege-based security model for jobs -- 更好的权限控制
    Naming of jobs and comments in jobs -- job命名和描述
    Stored, reusable schedules  -- 存储和重用存储过程

--常见用法

BEGIN
  DBMS_SCHEDULER.create_job (
    job_name        => 'test_full_job_definition',
    job_type        => 'PLSQL_BLOCK',
    job_action      => 'BEGIN DBMS_STATS.gather_schema_stats(''WJ''); END;',
    start_date      => SYSTIMESTAMP,
    repeat_interval => 'freq=hourly; byminute=0',
    end_date        => NULL,
    enabled         => TRUE,
    comments        => 'Job defined entirely by the CREATE JOB procedure.');
END;

运行os命令的例子

BEGIN
  DBMS_SCHEDULER.CREATE_JOB (
     job_name           => 'my_OS_job',
     job_type           => 'EXECUTABLE',
     job_action         => 'ls /tmp',
     repeat_interval    => 'FREQ=MINUTELY',
     enabled            => TRUE
  );
END;

--运行一个job

EXEC dbms_scheduler.run_job('TEST_FULL_JOB_DEFINITION');

SELECT * FROM dba_scheduler_jobs WHERE job_name = 'TEST_FULL_JOB_DEFINITION';

REPEAT_INTERVAL的例子

'FREQ=DAILY; BYDAY=SUN; BYHOUR=18;',
 
'freq=MINUTELY;interval=1',  
 
'freq=MINUTELY;interval=5',  
 
'freq=HOURLY;interval=1',    
 
'FREQ=DAILY; BYDAY=MON,TUE,WED,THU,FRI,SAT,SUN; BYHOUR=22;',

更多关于dbms_scheduler的用法可以常见官方文档

http://docs.oracle.com/cd/E11882_01/server.112/e25494/scheduse.htm#ADMIN13380

参考文档：

http://docs.oracle.com/cd/B10501_01/server.920/a96521/jobq.htm#9499
http://www.mandsconsulting.com/oracle-dbms_scheduler-vs-dbms_job-create-run-monitor-remove
http://docs.oracle.com/cd/E11882_01/server.112/e25494/scheduse.htm#ADMIN13380