This is the end of the module on Oracle processes. This module discussed the purpose of the Oracle significant background processes.
You should understand the difference between a database and an instance, and you should also be able to do the following:
- Explain the difference between a database and an instance
- Identify the major background processes of an Oracle instance, and explain their purpose
- Display a list of the background processes that are currently running
- Identify the instances running on your system based on a listing of process names
Oracle Database includes the following components:
- The Oracle Database instance, which is a collection of processes and memory
- A set of disk files that contain user data and system data
When you connect with SQL*Plus, you are connecting to the Oracle instance. Each instance has an instance ID, also known as a system ID (SID). Because there can be more than one Oracle instance on a host computer, each with its own set of data files, you must identify the instance to which you want to connect. For a local connection, you identify the instance by setting operating system environment variables.
For a remote connection, you identify the instance by specifying a network address and a database service name. For both local and remote connections, you must set environment variables to help the operating system find the SQL*Plus executable and to provide the executable with a
path to its support files and scripts. To connect to an Oracle instance with SQL*Plus, therefore, you must complete the following steps:
- Step 1: Open a Command Window
- Step 2: Set Operating System Environment Variables
- Step 3: Start SQL*Plus
- Step 4: Submit the SQL*Plus CONNECT Statement
Click the Exercise link below to answer some essay questions and submit them .
Oracle Instance Architecture - Exercise
The next module is about memory architecture
. It is a short module, and it's the last of the architecture modules.
After you are finished with that, we will move on to doing some more interesting things, like creating a database from scratch.