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

Chapter 3. Control the Scheduler

Oracle Scheduler does a lot of out of the box things, and if the demands are not too high, Oracle Scheduler can cover most of the situations. When your application has to run many thousands of jobs in an hour and log them over a long period, a little more attention is needed. In cases where the demands are high, we need to take care of a few more things to keep the system happy. What we need to do depends on how the Scheduler is used and what kind of load it is supposed to handle.

In this chapter, we will take a closer look at how we can control this beast. We will take a look at the privileges for job creation, job execution, and Scheduler management. We will also examine how to control logging retention and find a way to prevent jobs from running when the database starts.

Job creation

Like most object types in the database, as seen at the beginning of Chapter 1, Oracle enables us to create Scheduler objects. The privileges create job and create external job...