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

Job execution


It might look like kicking in an open door, but the job owner has automatic execution privileges on his or her own jobs. As dbms_scheduler works with authid current_user, the executing user also needs the privileges on the objects that are used in the job. Originally, Oracle had stored objects defined with definer's rights. This means that if you have an execute permission on a package, with definer's rights (the default), the package can use all the objects that it needs without having to call the user to have privileges on the objects that the package works on. With authid current_user, we run the package with the privileges of the user who calls the package. This means that if (for example) the package wants to insert a row into a table, the calling user needs to not only execute privilege on the package, but also insert privileges on the table. Scheduler objects that can be granted to others are—job_class and Program. In order to be able to associate a job with a job_class...