About Oracle Database
1-2 Oracle Database 2 Day DBA
Every chapter in Oracle Database 2 Day DBA has an associated Oracle By Example
lesson. The OBE steps through all tasks in the chapter and includes annotated
screenshots. In some cases, the OBE provides additional information to help you
complete the task.
At the end of each chapter, you can find the link to its associated OBE lesson. The
home page for the 2 Day DBA Oracle By Example series is as follows:
http://www.oracle.com/technology/obe/11gr2_2day_dba/index.html
In addition, Oracle University provides a related instructor-led course called Oracle
Database 11g: 2 Day DBA. Contact Oracle University for more information.
About 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 is composed of the following 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. Metadata, or
data about the data, is the collection of information on disk that permits Oracle
software to manage user data. An example of metadata is the data dictionary.
Control structures (such as the control file and online redo log files) ensure the
integrity, availability, and recoverability of user data.
■ 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.
See Also:
■ Chapter 4, "Configuring the Network Environment"
■ Chapter 5, "Managing the Oracle Instance"
■ Chapter 6, "Managing Database Storage Structures"
■ Oracle Database Concepts for more information about background
processes
■ Oracle Database Reference for more information about background
processes