11 November 2009

" Mastering Oracle Scheduler " Review

Recently, i have finished “MasteringOracle Scheduler in Oracle 11g Databases” book review, by Ronald Rood, from packtpublishing. The detail of the book is shown below:

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 – with serious price tags – 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.
Readthe full Table of Contents for Mastering Oracle Scheduler in Oracle 11gDatabases

What you will learn from this book
  • Create simple as well as complex jobs and schedule their execution according to your specific needs
  • Manage jobs independently of any particular platform so that they can be moved from one system to another easily
  • Create chains to link related programs, based on contingent outcomes
  • Flag the Scheduler to raise events when unexpected events occur
  • Manage logs to find out when jobs ran and analyze the runtime behavior based on recorded execution times
  • Combine your resource manager and Scheduler to get maximum throughput for managing thousands of jobs at a time
  • Run jobs on machines that do not have a running database using the remote job agent
  • Learn to debug jobs and make sure jobs run as expected

Here is brief summary of what each chapter covers:
Chapter 1 – Simple Jobs
The goal of this chapter is to get you, as quick as possible, going with the Scheduler. In the end you will automate simple tasks that are now maintained in for example cron, task manager, or the good old DBMS_JOB package.

Chapter 2 – Simple Chain
In this chapter you will see lot of possibilities of chains with many examples and explanations. In short, all you ever wanted to know about chains but were afraid to ask.

Chapter 3 – Control the Scheduler
For you people, living in an organization that requires strict job separation, this chapter will show how to make good use of the Scheduler and apply job separation.

Chapter 4 – Managing resources
This is a very impo
rtant chapter that explains how to crank up the power of a system to the limits by combining the Scheduler and resource manager. Here you will find how to get the best out of your system.

Chapter 5 – Getting out of the database
This chapter will be of great help in setting up remote external jobs, introduced in oracle 11g. How is this related to the old fashioned local external jobs that we have got to know since oracle 10g and why we should get rid of the old external jobs? Get your answers here.

Chapter 6 – Events
This chapter helps the reader to get a firm grip on events and explains how to make good use of events. Events sound like voodoo, but in the end are an extra tool found in the Scheduler.

Chapter 7 – Debugging the Scheduler
When the jobs get more complicated it gets harder to understand why something works out differently than planned. This chapter gives the reader a new look at how to follow and debug Scheduler jobs.

Chapter 8 – The Scheduler in Real Life
Here you will find some creative implementations of more or less common tasks – this time implemented using the Scheduler. This chapter gives working code with clear explanations. This broadens the horizon and will take down barriers that might exist between other environments and oracle.

Chapter 9 – Other configurations
This chapter shows how the Scheduler can be used in other configurations like standby databases and RAC.

Chapter 10 - Working remotely
This chapter shows how the Scheduler can be managed and monitored remotely through a web interface.
This is your practical guide to setting up a working environment and using Oracle Scheduler. Packed with simple examples and clear explanations, real-life scenarios are discussed to make you comfortable in implementing them in your own system.
Who this book is written for
This book is intended for Administrators and Developers who currently use tools like cron, DBMS_JOB, and the task manager, but who now want more control or who have a need to scale up to tools that can handle the network. Complex tasks can be built that easily control business process and enable the completion of important tasks in limited time.

The reader is expected to have some experience of Oracle Database Management, and a working knowledge of SQL and PL/SQL.

Cache affect In oracle

>sqlplus hr/hr@xe

SQL*Plus: Release - Production on ...

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release - Production
With the Partitioning, OLAP and Data Mining options

SQL> set autotrace traceonly statistics;

SQL> alter system flush shared_pool;

System altered.

SQL> alter system flush buffer_cache;

System altered.

SQL> select count(*) from table_a where column_a = 1;--first call

       2224  recursive calls
          0  db block gets
        638  consistent gets
         49  physical reads

          0  redo size
        335  bytes sent via SQL*Net to client
        376  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
         57  sorts (memory)
          0  sorts (disk)
          1  rows processed

SQL> select count(*) from table_a where column_a = 1; --second call, cache affect

          0  recursive calls
          0  db block gets
          2  consistent gets
          0  physical reads

          0  redo size
        335  bytes sent via SQL*Net to client
        376  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          1  rows processed