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

Window


Windows are all around us. In this context, a window specifies a period in time. In Oracle Resource Manager, we can use windows to trigger the start of jobs at a window's opening time, and stop jobs at its closing time. A window also has a Resource Manager plan that activates when the window opens.

Now, all we need to do is to activate this plan. If everything is working as intended, it should be possible to have many jobs running at the same time without losing performance for the normal users. As Oracle has an enabled maintenance plan that is coupled to all weekdays, you might find yourself wondering why your plan is not active anymore—the day after activating the Zaphod's plan. This is because the Zaphod's plan is not yet coupled to a window. Oracle has already defined the windows in which they intend to run standard maintenance tasks. For now, we will leave it that way and create a window called prod that is open 24 hours a day. This means we need to schedule the automated tasks...