Job scheduling from Oracle 10g with dbms_scheduler

Job scheduling from Oracle 10g with dbms_scheduler
In Oracle 10g the DBMS_JOB package is replaced by the DBMS_SCHEDULER package. The DBMS_JOB package is now depricated and in Oracle 10g it's only provided for backward compatibility. From Oracle 10g the DBMS_JOB package should not be used any more, because is could not exist in a future version of Oracle.

With DBMS_SCHEDULER Oracle procedures and functions can be executed. Also binary and shell-scripts can be scheduled.


Rights

If you have DBA rights you can do all the scheduling. For administering job scheduling you need the priviliges belonging to the SCHEDULER_ADMIN role. To create and run jobs in your own schedule you need the 'CREATE JOB' privilege.

With DBMS_JOB you needed to set an initialization parameter to start a job coordinator background process. With Oracle 10g DBMS_SCHEDULER this is not needed any more.

If you want to user resource plans and/or consumer groups you need to set a system parameter:

ALTER SYSTEM SET RESOURCE_LIMIT = TRUE;


Getting started quickly
To quickly get a job running, you can use code like this:

begin

dbms_scheduler.create_job(
job_name => 'DEMO_JOB_SCHEDULE'
,job_type => 'PLSQL_BLOCK'
,job_action => 'begin package.procedure(''param_value''); end; '
,start_date => '01/01/2006 02:00 AM'
,repeat_interval => 'FREQ=DAILY'
,enabled => TRUE
,comments => 'Demo for job schedule.');
end;
/

This schedules a pl/sql block to be executed daily starting 1/1/2006 02:00 AM.

You can schedule things like this, but DBMS_SCHEDULER can reuse components.

You can build a schedule using components like program, schedule, job, job class and window. We will now discuss these components in detail.

Program

The program component represents program-code that can be executed. This program code can have parameters. Code example


begin
dbms_scheduler.create_program (
program_name => 'DEMO_JOB_SCHEDULE'
,program_type => 'STORED_PROCEDURE'
,program_action => 'package.procedure'
,number_of_arguments => 1
,enabled => FALSE
,comments => 'Demo for job schedule.');


dbms_scheduler.define_program_argument (
program_name => 'DEMO_JOB_SCHEDULE'
,argument_position => 1
,argument_name => 'kol1'
,argument_type => 'VARCHAR2'
,default_value => 'default'
);
dbms_scheduler.enable(name => 'DEMO_JOB_SCHEDULE');
end;
/


The parameter program_type can have one of the following values: 'PLSQL_BLOCK', 'STORED_PROCEDURE','EXECUTABLE'.

dbms_scheduler also allows to execute shell scripts (Windows: *.bat files) and executables.


Schedule

A schedule defines the frequence and date/time specifics of the start-time for the job.

example code

begin

dbms_scheduler.create_schedule(
schedule_name => 'DEMO_SCHEDULE'
, start_date => '01/01/2006 22:00:00'
, repeat_interval => 'FREQ=WEEKLY'
, comments => 'Weekly at 22:00');
END;
/


To drop the schedule:

begin

dbms_scheduler.drop_schedule(
schedule_name => 'DEMO_SCHEDULE'
, force => TRUE );
end;
/

Calendar expresions can have one of these values: 'Yearly','Monthly','Weekly','Daily','Hourly','Minutely','Secondely'


Job

A job defines when a specific task will be started. This can be done by assigning a program to one or more schedules (or to a specific date/time). A job can belong to only 1 job class. Code example

begin

dbms_scheduler.create_job(
job_name => 'DEMO_JOB1'
, program_name =>'DEMO_JOB_SCHEDULE'
, schedule_name =>'DEMO_SCHEDULE'
, enabled => FALSE
, comments => 'Run demo program every week at 22:00');
dbms_scheduler.set_job_argument_value(
job_name => 'DEMO_JOB1'
, argument_position => 1
, argument_value => 'param1');
dbms_scheduler.enable('DEMO_JOB1');
commit;
end;

/


Or start shell script


begin

dbms_scheduler.create_job

(

job_name => 'RUN_SHELL1',
schedule_name => 'DEMO_SCHEDULE',
job_type => 'EXECUTABLE',
job_action => '/home/test/run_script.sh',
enabled => true,
comments => 'Run shell-script'
);
end;
/


Monitoring job-scheduling

Jobs can be monitored using Oracle Enterprise Manager 10g. It's also possible to use a number of views that have been created in Oracle 10g. We will discuss some of these views here.


To show details on job run:


select log_date
, job_name
, status
, req_start_date
, actual_start_date
, run_duration
from dba_scheduler_job_run_details


To show running jobs:

select job_name
, session_id
, running_instance
, elapsed_time
, cpu_used
from dba_scheduler_running_jobs;

To show job history:

select log_date
, job_name
, status
from dba_scheduler_job_log;


show all schedules:

select schedule_name, schedule_type, start_date, repeat_interval from dba_scheduler_schedules;

show all jobs and their attributes:

select * from dba_scheduler_jobs

show all program-objects and their attributes

select * from dba_scheduler_programs;

show all program-arguments:

select * from dba_scheduler_program_args;