一点一点学习jobs的各个方面比较长，比较烦，但是应该看完后会对jobs比较好的应用
一、学习准备
开始dbms_job学习前，先认识一个参数job_queue_processes
a、job_queue_processes参数决定了job作业能够使用的总进程数。
b、当该参数为0值，任何job都不会被执行，建议合理设置该值且至少大于1。
c、对于job运行时间也应该尽量合理的设置间隔以及启动时间。
d、如果同一时间内运行的Job数很多，过小的参数值导致job不得不进行等待。而过大的参数值则消耗更多的系统资源。
f、对于存在依赖关系的job，尽可能将其进行合并到一个job中，如使用chain等。
想细致了解的请前往
http://blog.csdn.net/robinson_0612/article/details/8694772
在使用dbms_jobs时首先确认job_queue_processes的值（10g系统默认为10）
SQL> SHOW PARAMETER JOB_QUEUE_PROCESSES; NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
job_queue_processes integer 10
另外10g开始提供了一个新的job管理包：DBMS_SCHEDULER
http://space.itpub.net/8858072/viewspace-425547
http://www.cnblogs.com/lanzi/archive/2012/11/23/2784815.html
二、创建第一个job
SQL> create table a(a date); Table created. SQL> create or replace procedure job_test as
2 begin
3 insert into a values(sysdate);
4 end;
5 / Procedure created. SQL> exec job_test; PL/SQL procedure successfully completed. SQL> select * from a; A
-------------------
2013-05-31 15:45:32
创建一个job任务，时间间隔为每秒一次
SQL>variable job1 number;--注意别漏了定义变量
SQL> begin
2 dbms_job.submit(:job1,'job_test;',sysdate,'sysdate+1/64800');
3 commit;
4 end;
5 / PL/SQL procedure successfully completed
也可以更清晰的使用这个方式建立job
variable job1 number;
begin
sys.dbms_job.submit(job => :job1,
what => 'job_test;',
next_date => sysdate,
interval => 'sysdate+1/64800');--每天64800秒，即每秒执行一次，但是实际oracle的jobs不能精确到秒，这里只是为了快速测试效果
commit;
end;
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
JOB N_DATE WHAT INTERVAL B
---------- ------------------- ---------- -------------------- -
4 2013-05-31 15:49:24 job_test; sysdate+1/64800 N
SQL> select count(*) from a;
COUNT(*)
----------
9
SQL> /
COUNT(*)
----------
10
SQL> /
COUNT(*)
----------
10
SQL> select * from a;
A
-------------------
2013-05-31 15:45:32
2013-05-31 15:48:58
2013-05-31 15:49:03
2013-05-31 15:49:08
2013-05-31 15:49:13
2013-05-31 15:49:18
2013-05-31 15:49:23
2013-05-31 15:49:28
2013-05-31 15:49:33
2013-05-31 15:49:38
2013-05-31 15:49:43
11 rows selected.
从实际执行结果看，秒级的任务并非按每秒执行，间隔在2-5秒间，原因位置，平时秒级的任务需求也没有，不做深入研究
三、修改job执行间隔
SQL> exec dbms_job.change(4,null,null,'sysdate+1/1440');
PL/SQL procedure successfully completed.
SQL> commit; --一定要记得commit否则重启后会丢失
Commit complete.
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
JOB N_DATE WHAT INTERVAL B
---------- ------------------- ---------- -------------------- -
4 2013-05-31 15:57:08 job_test; sysdate+1/1440 N
SQL> truncate table a;
Table truncated.
SQL> select * from a;
no rows selected
SQL> select * from a;
A
-------------------
2013-05-31 15:57:08
SQL> /
A
-------------------
2013-05-31 15:57:08
2013-05-31 15:58:08
2013-05-31 15:59:08
2013-05-31 16:00:08
2013-05-31 16:01:08
修改成功
但是有瑕疵，08秒，假如我想精确，可以通过oracle的trunc函数(最后实验结果告诉我trunc可以输出00秒，但是jobs不能精确到秒)
SQL> alter session set nls_date_format='YYYY-MM-DD HH24:MI:SS'; Session altered. SQL> select sysdate from dual; SYSDATE
-------------------
2013-05-31 16:02:25 SQL> select trunc(sysdate,'mi') from dual; TRUNC(SYSDATE,'MI')
-------------------
2013-05-31 16:02:00
再次修改job
SQL> exec dbms_job.change(4,null,null,'trunc(sysdate,''mi'')+1/1440');
PL/SQL procedure successfully completed.
SQL> commit;
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
JOB N_DATE WHAT INTERVAL B
---------- ------------------- ---------- -------------------- -
4 2013-05-31 16:12:00 job_test; trunc(sysdate,'mi')+ N
1/1440
SQL> select * from a;
.....
A
-------------------
2013-05-31 16:08:09
2013-05-31 16:09:09
2013-05-31 16:10:09
2013-05-31 16:11:09
2013-05-31 16:12:04
2013-05-31 16:13:04
2013-05-31 16:14:04
2013-05-31 16:15:04
2013-05-31 16:16:04
2013-05-31 16:17:04
2013-05-31 16:18:04
还是不完美，继续证实精确到秒的job无法实现--至少我测试结果如此
关于trunc的详细使用，可以参考后面第六小节
四、临时停止jobs
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
JOB N_DATE WHAT INTERVAL B
---------- ------------------- ---------- -------------------- -
4 2013-05-31 16:12:00 job_test; trunc(sysdate,'mi')+ N
1/1440
SQL> exec dbms_job.broken(4,true);
PL/SQL procedure successfully completed.
SQL> commit;
Commit complete.
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
JOB N_DATE WHAT INTERVAL B
---------- ------------------- ---------- -------------------- -
4 4000-01-01 00:00:00 job_test; trunc(sysdate,'mi')+ Y
1/1440
重新开始job
SQL> exec dbms_job.broken(4,false);
PL/SQL procedure successfully completed.
SQL> commit;
Commit complete.
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
JOB N_DATE WHAT INTERVAL B
---------- ------------------- ---------- -------------------- -
4 2013-05-31 16:36:24 job_test; trunc(sysdate,'mi')+ N
1/1440
五、删除jobs
SQL> exec dbms_job.remove(4);
PL/SQL procedure successfully completed.
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
no rows selected
SQL> rollback;--不commit咱rollback看看
Rollback complete.
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
JOB N_DATE WHAT INTERVAL B
---------- ------------------- ---------- -------------------- -
4 2013-05-31 16:36:24 job_test; trunc(sysdate,'mi')+ N
1/1440
--jobs又回来了
SQL> exec dbms_job.remove(4);
PL/SQL procedure successfully completed.
SQL> commit;
Commit complete.
SQL> select job,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') as n_date,what,interval,broken from user_jobs;
no rows selected
--commit后就真的没了
误删除后可以恢复所以记得正常删除需要commit
六、jobs的间隔设置之日期函数学习
如果jobs跟linux crontab那样 * * * * * 会觉得很时间设置很清晰
oracle感觉烦点
6.1 trunc()
先认识一个函数trunc()
这里只讨论trunc的date相关
语法：
TRUNC (datetime_exp, fmt)
其中：
date 一个表达式,该表达式标识一个日期和时间数。
fmt 日期格式，该日期将由指定的元素格式所截去。忽略它则由最近的日期截去
以下是一些常用的日期格式范例
1)SQL> select trunc(sysdate) from dual ; --返回当前日期，精确到凌晨0点0分 TRUNC(SYSDATE)
-------------------
2013-06-04 00:00:00 2)SQL> select trunc(sysdate, 'mm') from dual;--mm格式为返回当月第一天 TRUNC(SYSDATE,'MM')
-------------------
2013-06-01 00:00:00 3)SQL> select trunc(sysdate,'yy') from dual;--yy格式，返回当年第一天 TRUNC(SYSDATE,'YY')
-------------------
2013-01-01 00:00:00 4)SQL> select trunc(sysdate,'dd') from dual; --dd返回当前年月日，与trunc(sysdate)等效 TRUNC(SYSDATE,'DD')
-------------------
2013-06-04 00:00:00 5)SQL> select trunc(sysdate,'yyyy') from dual; --yy跟yy一样，返回当年第一天 TRUNC(SYSDATE,'YYYY
-------------------
2013-01-01 00:00:00 6)SQL> select trunc(sysdate,'d') from dual; --d返回本周第一天，按老美的，第一天是周日 TRUNC(SYSDATE,'D')
-------------------
2013-06-02 00:00:00 7)SQL> select trunc(sysdate, 'hh') from dual ; --hh返回当前时间，精确到 TRUNC(SYSDATE,'HH')
-------------------
2013-06-04 16:00:00 8)SQL> select trunc(sysdate, 'mi') from dual; --mi返回当前时间精确到分钟，TRUNC()函数没有秒的精确 TRUNC(SYSDATE,'MI')
-------------------
2013-06-04 16:29:00
再来几个函数
last_day,next_day,add_months
6.2 last_day
返回指定时间当月的最后一天
SQL> select last_day('2013-10-5') from dual;
LAST_DAY('2013-10-5
-------------------
2013-10-31 00:00:00
SQL> select last_day(sysdate) from dual;
LAST_DAY(SYSDATE)
-------------------
2013-06-30 18:16:30
想要下个月的3号
SQL> select last_day(sysdate)+3 from dual;
LAST_DAY(SYSDATE)+3
-------------------
2013-07-03 18:17:26
再组合下trunc
SQL> select trunc(last_day(sysdate)+3) from dual;
TRUNC(LAST_DAY(SYSD
-------------------
2013-07-03 00:00:00
再组合一个小时分钟
SQL> select trunc(last_day(sysdate)+3)+3/24+30/1440 from dual;
TRUNC(LAST_DAY(SYSD
-------------------
2013-07-03 03:30:00
n/24表示小时
n/1440表示分钟
n/64800表示秒
6.3 next_day
返回下一个星期某一天
next_day(date,n)
想要每周3早上3点
SQL> select next_day(sysdate,4) from dual;--按老美的每周第一天是周日，所以周三是4 NEXT_DAY(SYSDATE,4)
-------------------
2013-06-05 18:22:59
组合下trunc、小时、分钟
SQL> select trunc(next_day(sysdate,4))+3/24+30/1440 from dual; TRUNC(NEXT_DAY(SYSD
-------------------
2013-06-05 03:30:00
6.4 add_months
返回指定日期后的多少个月
add_months(date,n)
以当前日期为起始，每2个月后的今天的3：30
SQL> select trunc(add_months(sysdate,2))+3/24+30/1440 from dual; TRUNC(ADD_MONTHS(SY
-------------------
2013-08-04 03:30:00 SQL> select trunc(add_months(trunc(sysdate,'yy'),2))+3/24+30/1440 from dual; TRUNC(ADD_MONTHS(TR
-------------------
2013-03-01 03:30:00
也可以简单点具体到每2个月那一天
SQL> select trunc(add_months('2013-01-03',2))+3/24+30/1440 from dual;
TRUNC(ADD_MONTHS('2
-------------------
2013-03-03 03:30:00
有了上面的基础后我们来制定一些计划任务
6.5 来个需求试试
每月3号10:00执行job_test任务
SQL> variable job1 number;
SQL> begin
2 dbms_job.submit(:job1,'job_test;',sysdate,'trunc(last_day(sysdate)+3)+3/24+30/1440');
3 commit;
4 end;
5 / PL/SQL procedure successfully completed. SQL> set linesize 200
SQL> col job format 999
SQL> col what format a50
SQL> col interval format a50
SQL> col next_date format a50
SQL> select job,what,interval,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') from user_jobs; JOB WHAT INTERVAL TO_CHAR(NEXT_DATE,'
---- -------------------------------------------------- -------------------------------------------------- -------------------
8 job_test; trunc(last_day(sysdate)+3)+3/24+30/1440 2013-07-03 03:30:00
每周3凌晨3:30执行 job_test
SQL> variable job1 number;
SQL> begin
2 dbms_job.submit(:job1,'job_test;',sysdate,'trunc(next_day(sysdate,4))+3/24+30/1440');
3 commit;
end;
4 5 / PL/SQL procedure successfully completed. SQL>
SQL> select job,what,interval,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') from user_jobs; JOB WHAT INTERVAL TO_CHAR(NEXT_DATE,'
---- -------------------------------------------------- -------------------------------------------------- -------------------
8 job_test; trunc(last_day(sysdate)+3)+3/24+30/1440 2013-07-03 03:30:00
9 job_test; trunc(next_day(sysdate,4))+3/24+30/1440 2013-06-05 03:30:00
每天3点
SQL> variable job1 number;
SQL> begin
2 dbms_job.submit(:job1,'job_test;',sysdate,'trunc(sysdate+1)+3/24');
3 commit;
4 end;
5 / PL/SQL procedure successfully completed. SQL> select job,what,interval,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') from user_jobs; JOB WHAT INTERVAL TO_CHAR(NEXT_DATE,'
---- -------------------------------------------------- -------------------------------------------------- -------------------
10 job_test; trunc(sysdate+1)+3/24 2013-06-05 03:00:00
8 job_test; trunc(last_day(sysdate)+3)+3/24+30/1440 2013-07-03 03:30:00
9 job_test; trunc(next_day(sysdate,4))+3/24+30/1440 2013-06-05 03:30:00
一朋友还告诉我了一种拼接的方法，有兴趣的可以看看
每月3号早上10：00
variable job1 number;
begin
dbms_job.submit(:job1,'job_test;',sysdate,'to_date(to_char(add_months(sysdate,1),''yyyymm'')||''03 10:00:00'',''yyyy-mm-dd hh24:mi:ss'')');
commit;
end;
/
其他的...
每小时
dbms_job.submit(:job1,'job_test;',sysdate,'sysdate+1/24');
每十分钟
dbms_job.submit(:job1,'job_test;',sysdate,'sysdate+10/1440');
最后到指定某个特定时间点
variable job1 number;
begin
dbms_job.submit(:job1,'job_test;',to_date('2013-06-04 20:00:00','YYYY-MM-DD HH24:MI:SS'),'');
commit;
end;
/ SQL> select job,what,interval,to_char(next_date,'yyyy-mm-dd hh24:mi:ss') from user_jobs; JOB WHAT INTERVAL TO_CHAR(NEXT_DATE,'
---- -------------------------------------------------- -------------------------------------------------- -------------------
12 job_test; null 2013-06-04 20:00:00
在这里绕了点弯路，脑袋一直往前面习惯性的intervel设置
其实只执行一次next_date就妥妥的 -_-
七、dbms_job的具体语法
先以dbms_job.change为例
DBMS_JOB.CHANGE(
JOB IN BINARY_INTEGER, --job号
WHAT IN VARCHAR2， --执行什么
NEXT_DATE, --下一次执行时间
INTERVAL IN VARCHAR2， --执行间隔
INSTANCE IN BINARY_INTEGER DEFAULT NULL,
FORCE IN BOOLEAN DEFAULT FALSE
);
所以
exec dbms_job.change(4,null,null,'sysdate+1/1440');
__| |__ |___ |____________
| | | |
job号 what next_date interval
commit;
DBMS_Job包含以下子过程：
1、Broken()过程:更新一个已提交的工作的状态，可用于临时停止任务
PROCEDURE BROKEN
( JOB IN BINARY_INTEGER,
BROKENIN BOOLEAN,
NEXT_DATE IN DATE := SYSDATE
)
2、change()过程:用来改变指定工作的设置
DBMS_JOB.CHANGE(
JOB IN BINARY_INTEGER,
WHAT IN VARCHAR2,
NEXT_DATE,
INTERVAL IN VARCHAR2,
INSTANCE IN BINARY_INTEGER DEFAULT NULL,
FORCE IN BOOLEAN DEFAULT FALSE
);
3、Interval()过程:用来显式地设置重执行一个工作之间的时间间隔数。
PROCEDURE INTERVAL
( JOB IN BINARY_INTEGER,
INTERVAL IN VARCHAR2
)
4、Isubmit()过程:用来用特定的工作号提交一个工作
PROCEDURE ISUBMIT
( JOB IN BINARY_INEGER,
WHAT IN VARCHAR2,
NEXT_DATE IN DATE,
INTERVAL IN VARCHAR2,
NO_PARSE IN BOOEAN := FALSE
)
5、Next_Date()过程:用来显式地设定一个工作的执行时间
PROCEDURE NEXT_DATE
( JOB IN BINARY_INEGER,
NEXT_DATE IN DATE
)
6、Remove()过程:来删除一个已计划运行的工作
PROCEDURE REMOVE(JOB IN BINARY_INEGER);
7、Run()过程:用来立即执行一个指定的工作
PROCEDURE RUN(JOB IN BINARY_INEGER)
8、Submit()过程：工作被正常地计划好
PROCEDURE SUBMIT
( JOB OUT BINARY_INEGER,
WHAT IN VARCHAR2,
NEXT_DATE IN DATE,
INTERVAL IN VARCHAR2,
NO_PARSE IN BOOEAN := FALSE
)
9、User_Export()过程：返回一个命令，此命令用来安排一个存在的工作以便此工作能重新提交。
PROCEDURE USER_EXPORT
( JOB IN BINARY_INEGER,
MY_CALL IN OUT VARCHAR2
)
10、What()过程：可以用于更改要执行的任务
PROCEDURE WHAT
( JOB IN BINARY_INEGER,
WHAT IN OUT VARCHAR2
)
整理完上面的后，想想，以上这些难道要死记？要背手册？
其实...可以通过desc获得：
很多的dbms工具包都可以通过desc查看
SQL> desc dbms_job;
FUNCTION BACKGROUND_PROCESS RETURNS BOOLEAN
PROCEDURE BROKEN
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
BROKEN BOOLEAN IN
NEXT_DATE DATE IN DEFAULT
PROCEDURE CHANGE
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
WHAT VARCHAR2 IN
NEXT_DATE DATE IN
INTERVAL VARCHAR2 IN
INSTANCE BINARY_INTEGER IN DEFAULT
FORCE BOOLEAN IN DEFAULT
PROCEDURE INSTANCE
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
INSTANCE BINARY_INTEGER IN
FORCE BOOLEAN IN DEFAULT
PROCEDURE INTERVAL
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
INTERVAL VARCHAR2 IN
PROCEDURE ISUBMIT
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
WHAT VARCHAR2 IN
NEXT_DATE DATE IN
INTERVAL VARCHAR2 IN DEFAULT
NO_PARSE BOOLEAN IN DEFAULT
FUNCTION IS_JOBQ RETURNS BOOLEAN
PROCEDURE NEXT_DATE
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
NEXT_DATE DATE IN
PROCEDURE REMOVE
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
PROCEDURE RUN
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
FORCE BOOLEAN IN DEFAULT
PROCEDURE SUBMIT
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER OUT
WHAT VARCHAR2 IN
NEXT_DATE DATE IN DEFAULT
INTERVAL VARCHAR2 IN DEFAULT
NO_PARSE BOOLEAN IN DEFAULT
INSTANCE BINARY_INTEGER IN DEFAULT
FORCE BOOLEAN IN DEFAULT
PROCEDURE USER_EXPORT
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
MYCALL VARCHAR2 IN/OUT
PROCEDURE USER_EXPORT
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
MYCALL VARCHAR2 IN/OUT
MYINST VARCHAR2 IN/OUT
PROCEDURE WHAT
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
JOB BINARY_INTEGER IN
WHAT VARCHAR2 IN
暂时over，有了再补充
by cycsa
http://www.cnblogs.com/cycsa