Automating Tasks with the Scheduler

17Copyright © 2004, Oracle. All rights reserved.

Automating Tasks with the Scheduler

Copyright © 2004, Oracle. All rights reserved.17-2

Objectives

After completing this lesson, you should be able to:• Simplify management tasks by using the

Scheduler• Create a job, program, schedule, and window• Reuse Scheduler components for similar tasks• View information about job executions and job

instances


Scheduling Needs

Create month-end report on the last day of each month

Compute table andindex statistics

twice a day

Replicate table datavia materializedview refreshes

Generate daily report on invalid server access attempts

Start the batch load at 4:00 a.m.

Check for queued events every 10 minutes

Run daily job to backup

database


Scheduler Concepts

JobProgram

Arguments Arguments

Schedule

Job class Window

Resource plan

Window group

ResourceConsumer Group


Privileges for Scheduler Components

CREATE [ANY] JOBEXECUTE ANY PROGRAMEXECUTE ANY CLASSMANAGE SCHEDULER

EXECUTE ON <program or class>ALTER ON <job, program, or schedule>ALL ON <job, program, schedule, or class>

System and object privileges SCHEDULER_ADMIN role

CREATE JOB

CREATE ANY JOB

EXECUTE ANY PROGRAM

EXECUTE ANY CLASS

MANAGE SCHEDULER


Creating a Scheduler Job

There are many ways to create a job:

• Specifying the components in-line as part of the CREATE_JOB procedure

• Specifying the task directly and using a saved schedule

• Calling a saved program and a saved schedule

• Calling a saved program and specifying the schedule directly


Creating a Scheduler Job: Example

Create a job that calls a backup script every night at 23:00 (starting tonight).

BEGIN DBMS_SCHEDULER.CREATE_JOB( job_name=>'HR.DO_BACKUP', job_type => 'EXECUTABLE', job_action =>'/home/usr/dba/rman/nightly_incr.sh', start_date=>TRUNC(SYSDATE)+23/24, repeat_interval=>'TRUNC(SYSDATE+1)+23/24', /* next night at 11:00 PM */ comments => 'Nightly incremental backups');END;/


Setting the Repeat Interval for a Job

• Using a calendaring expression:

• Using a datetime expression:

repeat_interval=> 'FREQ=HOURLY; INTERVAL=4'repeat_interval=> 'FREQ=DAILY'repeat_interval=> 'FREQ=MINUTELY; INTERVAL=15'repeat_interval=> 'FREQ=YEARLY; BYMONTH=MAR,JUN,SEP,DEC; BYMONTHDAY=15'

repeat_interval=> 'SYSDATE + 36/24'repeat_interval=> 'SYSDATE + 1'repeat_interval=> 'SYSDATE + 15/(24*60)'


Calendaring Expressions

YEARLY

MONTHLY

WEEKLY

DAILY

HOURLY

MINUTELY

SECONDLY

INTERVAL(1-999)

BYMONTH

BYWEEKNO

BYYEARDAY

BYMONTHDAY

BYDAY

BYHOUR

BYMINUTE

BYSECOND

Frequency Interval Specifiers


Using Scheduler Programs

BEGIN DBMS_SCHEDULER.CREATE_PROGRAM( program_name => 'CALC_STATS2', program_action => 'HR.UPDATE_SCHEMA_STATS', program_type => 'STORED_PROCEDURE', enabled => TRUE);

DBMS_SCHEDULER.CREATE_JOB( job_name=>'HR.GET_STATS2', program_name=>'HR.CALC_STATS2', start_date=>'20-DEC-04 07.00.00 AM Greenwich', repeat_interval=> 'FREQ=HOURLY;INTERVAL=2', end_date => '20-DEC-05 07.00.00 AM Greenwich', comments => 'Explicitly scheduled job');END;/


Creating a Program Using EM


Specifying Schedules for a Job

Example schedules:

• Wednesday, December 26, 2002, at 2:00 p.m.

• Every fourth Thursday

• Every Monday at 8:00 a.m., starting on January 29, 2004, and ending on March 31, 2004

ScheduleStarttime

End timeor limit

One Timejob

Repeatingjob


Creating and Using Schedules

BEGIN DBMS_SCHEDULER.CREATE_SCHEDULE( schedule_name => 'stats_schedule', start_date => SYSTIMESTAMP, end_date => SYSTIMESTAMP + 30, repeat_interval => 'FREQ=HOURLY;INTERVAL=4', comments => 'Every 4 hours');

DBMS_SCHEDULER.CREATE_JOB( job_name => 'HR.GET_STATS', program_name => 'HR.CALC_STATS2', schedule_name => 'STATS_SCHEDULE');END;/


Using EM to Create Schedules


Advanced Scheduler Concepts

JobProgram

Arguments Arguments

Schedule

Job class Window

Resource plan

Window group

ResourceConsumer Group


Creating a Job Class


Creating a Job Class

EXECUTE DBMS_SCHEDULER.CREATE_JOB_CLASS( - job_class_name => 'ADMIN_JOBS', - resource_consumer_group => 'DAYTIME_JOBS', - logging_level => DBMS_SCHEDULER.LOGGING_OFF);

Job Class

Resource Consumer

GroupService

Log History

Logging Level


Job Logging

• By default, all job runs are logged.

• The amount of information logged can be controlled at the job class level.

EXECUTE DBMS_SCHEDULER.CREATE_JOB_CLASS( - job_class_name => 'ADMIN_JOBS', - resource_consumer_group => 'DAYTIME_JOBS', - logging_level => DBMS_SCHEDULER.LOGGING_RUNS, - log_history => 30);


Creating a Window

Create a window for the month of December that uses the END_OF_YEAR resource plan and is active every night from 6:00 p.m. to 6:00 a.m. Eastern Standard Time (EST).

BEGIN DBMS_SCHEDULER.CREATE_WINDOW( window_name => 'DEC_NIGHTS', resource_plan => 'END_OF_YEAR', start_date => '01-DEC-04 06.00.00 PM EST', repeat_interval => 'FREQ=DAILY; BYHOUR=18', duration => '0 12:00:00', end_date => '31-DEC-04 06.00.00 AM EST', comments => 'Every day at 6:00 PM');END;/


Prioritizing Jobs Within a Window

Daytime Window

APPL_JOBS

Job1 Job2

ADMIN_JOBS

Job4 Job5

OTHER

Job3

Job Priority

Job1 1

Job2 5

Job3 3

Job4 4

Job5 2


Enabling and Disabling Scheduler Components

• Enable the CALC_STATS2 program:

• Disable the GET_STATS job:

EXEC DBMS_SCHEDULER.ENABLE('HR.CALC_STATS2');

EXEC DBMS_SCHEDULER.DISABLE('HR.GET_STATS');


Managing Jobs

• Run a job:

• Stop a job:

• Drop a job, even if it is currently running:

DBMS_SCHEDULER.RUN_JOB('HR.JOB1');

DBMS_SCHEDULER.STOP_JOB('HR.JOB2');

DBMS_SCHEDULER.DROP_JOB('HR.JOB1,HR.JOB2, SYS.JOBCLASS1');


Managing Programs

• Enabling a program:

• Disabling a program:

• Dropping a program:

EXECUTE DBMS_SCHEDULER.DROP_PROGRAM( - program_name => 'HR.PROG1', - force => FALSE );

EXECUTE DBMS_SCHEDULER.ENABLE( - 'HR.PROG1,HR.PROG2');

EXECUTE DBMS_SCHEDULER.DISABLE( - 'HR.PROG1,HR.PROG2');


Managing Programs with EM


Managing Schedules

• CREATE_SCHEDULE• SET_ATTRIBUTE (to alter a schedule)

• DROP_SCHEDULE

EXEC DBMS_SCHEDULER.DROP_SCHEDULE( - schedule_name => 'HR.STATS_SCHEDULE');

EXEC DBMS_SCHEDULER.SET_ATTRIBUTE( - name => 'HR.STATS_SCHEDULE', - attribute => 'START_DATE', - value => '01-JAN-2004 9:00:00 US/Pacific');


Managing Windows

DBMS_SCHEDULER.OPEN_WINDOW( window_name =>'DEC_NIGHTS', duration => '1 0:00:00');

DBMS_SCHEDULER.CLOSE_WINDOW('DEC_NIGHTS');

DBMS_SCHEDULER.DROP_WINDOW( window_name =>'DEC_NIGHTS, DEC_DAYS', force => TRUE);

DBMS_SCHEDULER.DISABLE( name => 'SYS.DEC_NIGHTS', force=>TRUE);


Window Priority

An order of precedence applies for when windows overlap:

• The window with the highest priority opens first

• If windows have same priority, then the window that is active remains open

• If at the end of a window there are multiple windows defined, the window that has the highest percentage of time remaining, opens

• An open window that is dropped is automatically closed

8 a.m6 a.m 10 a.m 12 p.m. 2 p.m

W1 W2W3


Managing Attributes of Scheduler Components

• Change an attribute for a job:

• Remove a program comment by setting it to NULL:

BEGIN DBMS_SCHEDULER.SET_ATTRIBUTE( name => 'HR.GET_STATS', attribute => 'MAX_FAILURES', value => 3);END;/

EXEC DBMS_SCHEDULER.SET_ATTRIBUTE_NULL( - 'HR.CALC_STATS2','COMMENTS');


Managing Attributes of Scheduler Components

Retrieve attribute values for the GET_STATS job created by the HR user:

SELECT max_failures MAX_FAIL, job_priority, schedule_limit SCHED_LIMIT, logging_levelFROM user_scheduler_jobsWHERE job_name = 'GET_STATS'AND job_creator = 'HR';

MAX_FAIL JOB_PRIOR SCHED_LIMIT LOGGING_LEVEL-------- --------- ------------ -------------- 3 3 LOW


Managing Attributes of the Scheduler

You can set three attribute values at the global level, affecting all Scheduler components:

• default_timezone• max_job_slave_processes• log_history

EXEC DBMS_SCHEDULER.SET_SCHEDULER_ATTRIBUTE( - attribute => 'log_history', - value => '14');


Viewing Job Execution Details

• The DBA_SCHEDULER_JOB_RUN_DETAILS view has a row for each job instance.

• Each row contains information about the job execution for that instance.

SELECT job_name, status, error#, run_durationFROM USER_SCHEDULER_JOB_RUN_DETAILS;

JOB_NAME STATUS ERROR# RUN_DURATION ---------------- ------ ------ ------------GATHER_STATS_JOB SUCCESS 0 +000 00:08:20 PART_EXCHANGE_JOB FAILURE 6576 +000 00:00:00


Viewing Job Logs

The DBA_SCHEDULER_JOB_LOG view has a row for each job operation or modification.

SELECT job_name, operation, ownerFROM ALL_SCHEDULER_JOB_LOG;

JOB_NAME OPERATION OWNER ----------- --------- ------ GET_STATS2 ALTER HRTESTJOB RUN HRTESTJOB RETRY_RUN HRTESTJOB FAILED HRTESTJOB DROP HRCOMPUTE_STATS CREATE HR


Purging Job Logs

You can purge the job logs:

• Automatically, through the PURGE_LOG job using default values

• Using the PURGE_LOG job, but modifying the conditions that determine when entries are purged

• On demand, by calling the DBMS_SCHEDULER.PURGE_LOG procedure

EXECUTE DBMS_SCHEDULER.PURGE_LOG( - log_history => 1, - job_name => 'TESTJOB');


Data Dictionary Views

• [DBA | ALL | USER]_SCHEDULER_JOBS• [DBA | ALL | USER]_SCHEDULER_JOB_ARGS• [DBA | ALL | USER]_SCHEDULER_RUNNING_JOBS• [DBA | ALL | USER]_SCHEDULER_JOB_LOG• [DBA | ALL | USER]_SCHEDULER_JOB_RUN_DETAILS• [DBA | ALL | USER]_SCHEDULER_PROGRAMS• [DBA | ALL | USER]_SCHEDULER_PROGRAM_ARGS• [DBA | ALL | USER]_SCHEDULER_SCHEDULES• [DBA | ALL]_SCHEDULER_JOB_CLASSES• [DBA | ALL ]_SCHEDULER_WINDOWS• [DBA | ALL ]_SCHEDULER_WINDOW_DETAILS• [DBA | ALL ]_SCHEDULER_WINDOW_LOG


Summary

In this lesson, you should have learned how to:• Simplify management tasks by using the

Scheduler• Create a job, program, schedule, and window• Reuse Scheduler components for similar tasks• View information about job executions and job

instances


Practice 17 Overview: Automating Tasks with the Scheduler

This practice covers the following topics:

• Creating a job that runs a program outside of the database

• Creating a program and a schedule

• Creating a job that uses a program and a schedule

• Altering the program and schedule for the job and observing the behavior change of the job

• Monitoring job runs

Documents

Automating Tasks with the Scheduler