Database Reference
In-Depth Information
3
Oracle Database Architecture
In this chapter:
What are the basic architectural concepts of Oracle Database?
What is the Oracle instance?
What is the physical structure of an Oracle database?
How do you start up and shut down a database?
Enhancing the basic physical architecture of an Oracle database.
Let's begin with some very basic concepts.
3.1
The Basic Concepts
Oracle Database 10
is a relational database management system
(RDBMS), which means that it is a set of software programs that handles
the storage of information, the security for access to the information, and
the connections between various portions of the information.
Once you have installed the RDBMS software, you can create an Oracle
instance and a database. Figure 3.1 shows all three of these elements installed
on one computer, which is the typical way to install and run the software.
The database is made up of datafiles stored on the hard disks of the
computer. This is where all of your information will be stored. To add
information into the database, you must start up an Oracle instance. Once
started, your computer will be running a set of background processes,
which manage and manipulate the datafiles, among other things. You also
have a memory area called the System Global Area (SGA) that is reserved
for Oracle's use. Oracle stores as much information as possible in its mem-
ory to speed up the processing time of whatever operation you do, from
retrieving data in a special sorted format (which you will learn how to do in
g
Search WWH ::




Custom Search