Book Image

Mastering Oracle Scheduler in Oracle 11g Databases

By : Ronald Rood
Book Image

Mastering Oracle Scheduler in Oracle 11g Databases

By: Ronald Rood

Overview of this book

Scheduler (DBMS_SCHEDULER) is included in Oracle Database and is a tool for the automation, management, and control of jobs. It enables users to schedule jobs running inside the database such as PL/SQL procedures or PL/SQL blocks, as well as jobs running outside the database like shell scripts. Scheduler ensures that jobs are run on time, automates business processes, and optimizes the use of available resources. You just need to specify a fixed date and time and Scheduler will do the rest. What if you don't know the precise time to execute your job? Nothing to worry about, you can specify an event upon which you want your job to be done and Scheduler will execute your job at the appropriate time. Although scheduling sounds quite easy, it requires programming skills and knowledge to set up such a powerful, intelligent scheduler for your project. This book is your practical guide to DBMS_SCHEDULER for setting up platform-independent schedules that automate the execution of time-based or event-based job processes. It will show you how to automate business processes, and help you manage and monitor those jobs efficiently and effectively. It explains how Scheduler can be used to achieve the tasks you need to make happen in the real world. With a little understanding of how the Scheduler can be used and what kind of control it gives, you will be able to recognize the real power that many known enterprise-class schedulers ñ with serious price tags ñ cannot compete with. You will see how running a specific program can be made dependent on the successful running of certain other programs, and how to separate various tasks using the built-in security mechanisms. You will learn to manage resources to balance the load on your system, and gain increased database performance.
Table of Contents (15 chapters)
Mastering Oracle Scheduler in Oracle 11g Databases
Credits
About the Author
About the Reviewers
Preface

Running the chain


To run the job chain you can use the following:

begin
dbms_scheduler.run_job
(
job_name => 'j_cold_backup', use_current_session => false
);
end;

When the job is running, check the contents of the user_scheduler_running_jobs and user_scheduler_running_chains views. Officially, it is impossible for a chain to be listed in *_scheduler_running_chains without it being listed in scheduler_running_jobs as well. If you find this situation on your system, you need to apply the patch for bug 5705385. This bug is fixed in 11.1.0.7 and 10.2.0.5 with back ports available to 10.2.0.4 and 10.2.0.3.

In the user_scheduler_running_chains view, the complete execution of the chain is visible—as long as the chain is running, of course. This means that all the steps that are defined for the chain are visible, including step_name, state, error_code, start_time, and duration. We can use these steps to see how the chain progresses and what steps are still waiting to get started. step_job_subname...