Getting Started DB 11g - Basic Definitions

The Oracle Database Administrator

The Oracle DB Administrator (DBA) is the one who is responsible for the overall operation of Oracle Database. In this chapter Oracle describe common DBA tasks and tools. This chapter contains the following sections:

Oracle Database

• Oracle Database is a relational database with object and Extensible Markup Language (XML) capabilities. 
• In a relational database, all data is stored in two-dimensional tables that are composed of rows and columns. 
• Oracle Database enables you to store data, update it, and efficiently retrieve it, with a high degree of performance, reliability, and scalability.

Oracle Database elements:

• The Oracle software that you install on your host computer
  
• The database, which is a collection of physical files on one or more disks
  The database contains user data, metadata, and control structures.
  
• The Oracle instance, which is composed of the following:
  
  • The background processes, which are the operating system processes or threads that perform the work of accessing, storing, monitoring, and recovering user data, metadata, and control files associated with the database
    
  • The shared memory areas used by the background processes
    
• Server processes that perform work on behalf of connected users and applications, and the memory and temporary storage used by these processes. Server processes parse and execute SQL statements, and retrieve and return results to the user or application.
  
• Oracle Net, which is a software layer that enables client applications and Oracle Database to communicate over a network, and the Oracle Net listener, which is a process that listens for connection requests from the network.
  

Oracle DBA Tasks

• Installing Oracle software
  
• Creating Oracle databases
  
• Performing upgrades of the database and software to new release levels
  
• Starting and shutting down the database instance
  
• Managing the storage structures of the database
  
• Managing users and security
  
• Managing database objects, such as tables, indexes, and views
  
• Backing up the database and performing recovery operations when necessary
  
• Monitoring the state of the database and taking preventive or corrective action as required
  
• Monitoring and tuning database performance
  
• Diagnosing and reporting critical errors to Oracle Support Services
  

In a small to medium-sized database environment, you might be the sole person performing these tasks. In large, enterprise environments, the job is often divided among several DBAs.

Oracle DBA Tools

Following are some products, tools, and utilities you can use to achieve your goals as a database administrator:

• Oracle Universal Installer (OUI) is a utility that installs your Oracle software and options. It can automatically start Oracle Database Configuration Assistant to install a database.
  
• Oracle Database Configuration Assistant (DBCA) is a utility that creates a database from templates or you can create your own. It enables you to copy a preconfigured seed database, thus saving the time and effort of generating and customizing a new database.
  
• Database Upgrade Assistant which is a tool that guides you through the upgrade of your existing database to a new Oracle Database release.
  
• Net Configuration Assistant (NETCA) is a utility that enables you to configure listeners and naming methods, which are critical components of the Oracle Database network.
  
• Oracle Enterprise Manager Database Control which is a Web-based interface which is used to  manage your database and provides an interface for performance advisors and for Oracle utilities such as SQL*Loader and Recovery Manager (RMAN).
  
  Oracle also offers separately licensed Oracle Enterprise Manager management packs, management plug-ins, and other products you can purchase to enhance the capabilities of Oracle Enterprise Manager in specific environments.
  
  Regards
  Mostafa