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

RAC


When the jobs you are running depend on things other than just the database, it might be interesting to know what these other things are, and where they can be found. There are several ways to control which instance a job is going to run, some of which are:

  • Define instance_id in the job definition

  • Use instance_stickiness in the job definition

  • Define service_name in the job class definition for the job

To be able to show what exactly happens, we need an RAC installation. The RAC installation used here runs on two nodes—oralin01 and oralin02—using the shared storage that is exported as iSCSI disks from the of01 server running openfiler. The database called "shields" is using the iSCSI disks through the ASM. The instances of this database are shields1 and shields2. In the default setup, every instance of the cluster supports the service whose name is the same as the database name. For demonstration purposes, the services departures and arrivals have been defined. The preferred instance...