Book Image

Oracle Database 11g : Underground Advice for Database Administrators

By : April Sims
Book Image

Oracle Database 11g : Underground Advice for Database Administrators

By: April Sims

Overview of this book

Today DBAs are expected to deploy and manage large databases with quality service and little to no downtime. The DBA's main focus is on increasing productivity and eliminating idle redundancy throughout the enterprise. However, there is no magic set of best practices or hard and fast rules that DBAs need to follow, and this can make life difficult. But if DBAs follow some basic approaches and best practices, tasks can be performed more efficiently and effectively.This survival guide offers previously unwritten underground advice for DBAs. The author provides extensive information to illuminate where you fit in, and runs through many of the tasks that you need to be watchful of, extensively covering solutions to the most common problems encountered by newcomers to the world of Oracle databases.The book will quickly introduce you to your job responsibilities, as well as the skills, and abilities needed to be successful as a DBA. It will show you how to overcome common problems and proactively prevent disasters by implementing distributed grid computing—scalable and robust—with the ability to redeploy or rearchitect when business needs change. Reduce downtime across your enterprise by standardizing hardware, software, tools, utilities, commands, and architectural components.This book will also help you in situations where you need to install Oracle Database 11g or migrate to new hardware making it compliant with a Maximum Availability Architecture. By the end of this book you will have learned a lot and gained confidence in your abilities. You will be armed with knowledge as to which tools are best used to accomplish tasks while proactively moving towards an automated environment.
Table of Contents (14 chapters)
Oracle Database 11g—Underground Advice for Database Administrators
Credits
About the author
About the reviewers
Preface
Index

Dump block


Dump block gives you the view of the data at the block level, the smallest piece of storage for the data. Working through this chapter allows you to apply concepts of how data moves, block by block, through the physical structures of the database, really solidifying how transaction integrity is maintained. You would only use dump block on a production system with an Oracle Support Engineer, which is usually done during advanced recovery situations. The dump block is often used to determine the level and extent of corruption and what data can be recovered. It can also be used to resolve some tuning and performance issues.

Note

Do not do this in a production database.

Our examination of data blocks starts in Section 12-6 of the Concepts Manual.

Data block format: "Every Oracle data block has a format or internal structure that enables the database to track the data and free space in the block. This format is similar whether the data block contains table, index, or table cluster data...