Chapter 1, When to Step Away from the Keyboard, answers the question "What does a DBA do all day?" It contains a comprehensive list of prioritized tasks that the average DBA is responsible for. A common theme throughout the book is introduced in this chapter: Tools should be extensible, flexible, and ubiquitous. Included in this chapter is a list of commonly seen mistakes that can be easily avoided by adopting recommended practices. Emphasis is placed on the attitude and philosophy that a DBA should have while doing their job as a valuable team member.

Chapter 2, Maintaining Oracle Standards, discusses "standards" such as Oracle's Optimal Flexible Architecture, Unix shell scripting, code and configuration basics. This is meant to provide a solid foundation designed to reduce future maintenance. This is where your dedication to detail comes into play, as it takes work to enforce standards, especially when the personnel in your department change. A DBA should be comfortable with the fact that a migration to the next patch set, version, or hardware replacement will always be in progress. This requires multiple Oracle Homes with completely separate environments that can be easily switched; this chapter outlines how to accomplish this goal. The new 11g Automatic Diagnostic Repository features, for diagnosing and repairing certain types of failures, will be outlined in the chapter as well.

Chapter 3, Tracking the Bits and Bytes, covers how data moves from one database component to the next; the mechanics or essential architectural infrastructure at the block level; what the data in a datafile, redo, undo, or archivelog actually looks like; and how the database keeps up with SCN changes. Dumping database blocks provides the raw hexadecimal values that convert to the characters that the end user sees at the application level. Other utilities such as LogMiner can be used to access information from certain database components, as well as the very basic Unix command strings. These essential concepts will provide you with the confidence that you can survive any disaster that you may have to tackle. Corruption prevention and detection is covered because this is one of the real tests for excelling at your job. No one really wants to have to fix corruption when it happens, because the data becomes unrecoverable fast.

Chapter 4, Achieving Maximum Uptime, covers redundancy at all levels: hardware, software, databases, ASM, SAN(s), and load balancers. Databases become redundant with Data Guard and RAC. This chapter offers an introduction to network and SQL*Net tuning for all types of implementations. Achieve the smallest outage windows by moving to rolling upgrades, ensuring there is some sort of backup plan for important personnel as well as documenting configurations with Oracle Configuration Manager. There are always single points of failure in every organization; identifying them is the first step on the path to a fully documented disaster recovery plan.

Chapter 5, Data Guard and Flashback, explains that the combination of Oracle's Flashback and Data Guard makes recovery scenarios, stress testing, and hot fix patching on a physical standby possible by making the database read and write temporarily. Using both Data Guard and Flashback in tandem can reduce or eliminate downtime for the primary database in certain types of recovery situations. It may reduce or eliminate the need for duplication of hardware for testing purposes. Several scenarios are outlined in detail, along with recommendations for implementations that fulfill disaster recovery goals.

Chapter 6, Extended RMAN, covers the essential tool for DBAs—RMAN, which is just complicated enough to warrant its own chapter. In this chapter, we will provide the foundations for writing your own scripts to get you started using this utility today. While the previous standard backups consisted of either a basic cold or hot version, RMAN does that and also adds even more flexibility when automating backup (and even recovery) routines. RMAN is the basic utility behind several types of disaster recovery and migration tasks such as: Creating Physical and Logical Standby(s). You can restore between different versions and migrate to new hardware using Transportable Tablespaces. RMAN is also involved with 11g's ADR Detected Failure Repairs, as well as duplication across the network (both local and remote).

Chapter 7, Migrating to 11g: A Step-Ordered Approach, talks about how migrating to a newer Oracle Database version doesn't have to be confined to a single outage period. Several interim steps can be done ahead of time to certain compatible components, saving valuable time. In a general sense, Oracle is backwards compatible for making that transition from an earlier version to a later one. The following components can be upgraded while still remaining compatible with earlier versions of Oracle:

This is an essential guide for upgrading to 11g using a multiple home environment: Cloning Oracle homes, Oracle Universal Installer (interactive, silent, and suppressed modes), RMAN catalog, and SQL Net. All of the options for performing upgrades are touched on in this book: DBUA, Manual Method, Export/Import, Data pump, TTS, RMAN, Physical Standbys, and the newer Transient Logical Standby.

Chapter 8, 11g Tuning Tools, covers ORION, TRCANLZR, and Statspack utilities. While it is easy to show someone how to use a tool, it takes experience to correctly interpret the results you get. This chapter will also cover different free-source, load-testing tools for forecasting trends of CPU utilization and I/O; in other words predicting the approximate time to purchase new hardware before the end user experiences degraded performance. 11g features such as SQL Plan Management will be covered along with Oracle's own Enterprise Manager tuning tools. A large portion of this chapter is dedicated to the migration path for upgrading the query optimizer using SQL Plan Management from 10g to 11g. Start a new paragraph from here, you might still be overwhelmed with all of the work set before you, and that's is why you've bought this book in the first place. This is a book you will keep for a long time, referring back again and again for each new project. It will be especially handy to show management when they start altering your job description. It is our hope that this is only a starting place for your career as a DBA and that by reading this book, you will share the knowledge with your peers as an active participant in Oracle User Groups.

It would be helpful if you have some knowledge of SQL and are comfortable with the Unix operating system, but this is not absolutely essential. For those new to these technologies, keep the documentation nearby to use as a reference. This book is written for the Unix operating system, but you may only have access to a Windows operating system such as a desktop for testing purposes. There are tools, such as Cygwin (for Windows), which enable many of the same operating system commands to work on both Unix and Windows.

This book focuses on 11g Release 2 version with a reference to general Unix operating system commands. Previous versions of Oracle are also referenced when it applies to migration or upgrading to 11g as the topic. The Oracle Database Installation Guide for the version you are installing will have the prerequisite hardware requirements. The best place to start for the latest documentation and Oracle software downloads is the Oracle Technology Network (OTN) website: http://otn.oracle.com.

This is for you if you find yourself in charge of an Oracle Database (understanding the full responsibility that goes with such a position), but are unsure of what tasks you need to perform. It can be easy to feel overwhelmed, so this reference is designed as a sanity check, whether you are a single employee or the DBA manager of several employees, or whether you are taking over an existing position or taking up a newly created one.

You are a person that wants to be proactively preventing disasters instead of simply keeping ahead of the next problem. In doing so, you'll help counter one of the major causes of professional burnout. This book is meant to make your technical transition to a DBA career easier and more efficient while educating you on how to reduce some of the most common mistakes.

You may be someone who needs guidance for migrating to 11g or implementing Oracle's Maximum Availability Architecture. This book is also meant to map out the migration options available when purchasing new hardware, giving you the opportunity to change the way your Oracle software is implemented, and to make it more Optimal Flexible Architecture compliant. This book will be useful when you are assigned the responsibility of making any sort of change in your Oracle environment—installations, migrations, upgrades, as well as patching. Take a few moments to read through the recommendations and suggestions for automating the maintenance tasks required for your applications to make them more redundant, flexible, and tolerant of future changes.

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text are shown as follows: "We can include other contexts through the use of the include directive."

A block of code is set as follows:

run {
SET CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO ‘/backuplocation/%F';
restore controlfile from autobackup;
alter database mount;
}

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "clicking the Next button moves you to the next screen".

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