Book Image

OCA Oracle Database 11g: Database Administration I: A Real-World Certification Guide

Book Image

OCA Oracle Database 11g: Database Administration I: A Real-World Certification Guide

Overview of this book

Oracle Database Server is the most widely used relational database in the world today. This book gives you the essential skills to master the fundamentals of Oracle database administration and prepares you for Oracle DBA certification."OCA Oracle Database 11g: Database Administration I: A Real-World Certification Guide" prepares you to master the fundamentals of Oracle database administration using an example driven method that is easy to understand. The real world examples will prepare you to face the daily challenges of being a database administrator.Starting with the essentials of why databases are important in today's information technology world and how they work, you are then guided through a full, customized installation of the Oracle software and creating your own personal database. We then examine fundamental concepts of Oracle, including architecture, storage structures, security, performance tuning, networking, and instance management. Finally, we take an in-depth look at some of the most important concepts in the daily life of an Oracle DBA - backup, recovery, and data migration."OCA Oracle Database 11g: Database Administration I: A Real-World Certification Guide" provides you with the skills you need in order to become a successful Oracle DBA, both for certification and real life tasks.
Table of Contents (24 chapters)
OCA Oracle Database 11g: Database Administration I: A Real-World Certification Guide
Credits
Foreword
About the Author
About the Reviewer
www.packtpub.com
Preface
Index

Understanding the lifecycle of a transaction


In order to understand concurrency, we need to understand the concept of a transaction. A transaction, in database terms, is a discrete unit of work within the database that accomplishes a certain task. Transactions allow groups of statements to be executed together, to allow for correct recovery in the event of failure. Transaction control is the act of manipulating the timing and execution of transactions. Let's begin this section with an example that demonstrates the importance of transaction control.

Examining the rules of a transaction

In database terms, transactions generally involve statements from the SQL sublanguage called Data Manipulation Language (DML). The SELECT, INSERT, UPDATE, and DELETE statements are generally categorized as DML, although some definitions exclude the SELECT statements. They also involve statements such as COMMIT and ROLLBACK, which are referred to as Transaction Control Language (TCL). In the following example...