Sybex OCA Oracle 10g Administration I Study Guide phần 3 pdf

Using the Oracle Database Configuration Assistant 95

The size of the Flash Recovery area defaults to 2048MB and can be set larger or smaller by

changing the Flash Recovery Size setting.

Enabling Archive Logging

From the Recovery Configuration screen, you also have the ability to enable the Oracle archive

logging feature. Archive logging is the mechanism Oracle uses to enable you to perform point￾of-failure recovery of a database. To enable Archive Logging, mark the Enable Archiving check

box. Once you do so, the button Edit Archive Mode Parameters will be enabled. If you click this

button, you are presented with a screen that enables you to set the various parameters that are

used to configure archive logging (see Figure 2.15).

We will explore archive logging in more detail in Chapter 10.

After completing the Recovery Configuration screen, click Next. You will then be presented

with the Database Content screen.

Database Content

If you chose to create a custom database in the Database Templates screen, you will be pre￾sented with the Database Content screen as shown in Figure 2.16.

FIGURE 2.15 The DBCA Edit Archive Mode Parameters screen

4367.book Page 95 Wednesday, October 13, 2004 1:18 PM

96 Chapter 2 Creating and Controlling a Database

FIGURE 2.16 The DBCA Database Content screen

You use the options on this screen to specify which Oracle database components you want

to install. Table 2.3 lists and describes the components that can be included and configured

automatically by the DBCA.

TABLE 2.3 Oracle Optional Components

Component Description

Oracle Text Provides support for multimedia content such as audio

and video.

Oracle OLAP Provides facilities for creating and deploying online analyti￾cal processing applications

Oracle Spatial Provides the components and infrastructure for Oracle to

manage and maintain geographic and spatial information

such as map coordinates.

Oracle Data Mining Adds a set of analytical tools and extended algorithms to

the database to facilitate data mining.

Oracle Ultra Search Provides capabilities to perform extended text and searches

within the Oracle database.

4367.book Page 96 Wednesday, October 13, 2004 1:18 PM

Using the Oracle Database Configuration Assistant 97

Click the Standard Database Components button to display any additional standard fea￾tures that Oracle will automatically configure for you and recommend as part of a standard

database installation (see Figure 2.17). These features are the Oracle JVM, Oracle Intermedia,

and Oracle XML DB.

Sample Schemas and Custom Scripts

The DBCA also lets you install examples of actual working databases. Oracle provides a set of

example schemas and applications that use these schemas. You can install these sample schemas

now or later by running a series of SQL scripts.

These sample schemas include the following:

Human Resources

Order Entry

Product Media

Sales History

Queued Shipping

To select these schemas, click the Sample Schemas tab in the DBCA Database Content

screen, mark the Sample Schemas check box, and click Next (see Figure 2.18).

FIGURE 2.17 The DBCA Standard Database Components box

Oracle Label Security Manages and controls access to sensitive information

within the database.

Sample Schemas Provides working examples of how to configure and use

certain extended features of the Oracle database.

Enterprise Manager Repository Specifies the location of the schema used to manage the

content of the OEM repository. If you chose to do local man￾agement of your database, this schema is required.

TABLE 2.3 Oracle Optional Components (continued)

Component Description

4367.book Page 97 Wednesday, October 13, 2004 1:18 PM

98 Chapter 2 Creating and Controlling a Database

FIGURE 2.18 DBCA Database Content Sample Schemas Tab

These schemas are designed to provide you with working examples of how to use and imple￾ment a variety of features within Oracle. For example, the Product Media schema shows how

to use the Oracle Intermedia option, which is used to manage binary large objects (BLOBs) such

as images and sound clips.

If you choose to create the sample schemas, Oracle creates a tablespace called EXAMPLES and

stores all the necessary tables within that tablespace. Be aware that this adds about 130MB to

your database definition.

You can also run custom scripts as part of the database creation process. Click the Custom

Scripts tab in the Database Content screen to enter the names and locations of the custom scripts

that you want to run at database creation (see Figure 2.19).

For example, you might want the DBCA to automatically create the schema and define the

tables that you will use for this database. You can create a script that performs all the necessary

work and have the DBCA run the script as part of the database creation process. The custom

scripts are run using the command-line utility SQL*Plus, so you will have to define a user ID

and password within the body of the script. For example, your script might contain the line:

connect some_userid/some_password

This line directs Oracle to connect to the current Oracle database, which is determined by your

ORACLE_SID environment variable using the supplied user ID and password.

After completing the Database Content screen, click Next. You will then be presented with

the Initialization Parameters screen.

4367.book Page 98 Wednesday, October 13, 2004 1:18 PM

Using the Oracle Database Configuration Assistant 99

FIGURE 2.19 The DBCA Database Content Custom Scripts tab

Initialization Parameters

You use the Initialization Parameters screen to define the various initialization parameter set￾tings used to configure size and setup characteristics of the Oracle instance. The following four

tabs are categorized according to the parameters used to manage the Oracle instance:

Memory

Sizing

Character Sets

Connection Mode

Let’s take a look at each of these tabs and what settings you can manage under each tab.

The Memory Tab

You use the options on the Memory tab to control the size of the database parameters that con￾figure the overall memory footprint of the Oracle instance (see Figure 2.20). There are two gen￾eral approaches to managing the memory database parameters: Oracle can set and manage

most of the parameters for you, or you can customize each of the initialization parameters for

your specific database.

If you choose the Typical setting, Oracle allocates memory to the various components within

the Oracle System Global Area (SGA) and Process Global Area (PGA). This memory allocation

is automatic and is a percentage of the overall physical memory available on the server. The

default is 40 percent of total memory available, but you can change this setting. If you choose

this setting, click the Show Memory Distribution button to see how Oracle will allocate the

memory between the SGA and the PGA.

4367.book Page 99 Wednesday, October 13, 2004 1:18 PM