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 100 Chapter 2  Creating and Controlling a Database FIGURE 2.20 The Memory tab in the Initialization Parameters screen If you choose the Custom option, you have full control over how much each of the specific areas of the SGA will take. The main areas that you will configure are the Shared Pool, Buffer Cache, Java Pool, Large Pool, and PGA size. Each of the settings maps to a specific Oracle parameter. The Sizing Tab You use the options on the Sizing tab (see Figure 2.21) to configure the block size of your data- base and the number of processes that can connect to this database. The Block Size setting cor- responds to the smallest unit of storage within the Oracle database. All storage of database objects (tables, indexes, and so on) are governed by the block size. The block size defaults to 8KB, but you can modify it. Once the database is created, you cannot modify this setting. The maximum and minimum size of an Oracle block depends on the operating system. Gen- erally, 8KB is sufficient for most transaction-oriented applications, and larger block sizes such as 16KB and higher are used in data warehouse–type applications. The Processes setting specifies the maximum number of simultaneous operating system pro- cesses that can be connected to this Oracle database. You must include at least six processes for each of the Oracle background processes. You can increase this number on this screen. This parameter does have a bearing on the overall size of your Oracle instance. The larger you make this number, the more room Oracle must reserve in the SGA to track the processes. 4367.book Page 100 Wednesday, October 13, 2004 1:18 PM Using the Oracle Database Configuration Assistant 101 FIGURE 2.21 The Sizing tab in the Initialization Parameters screen The Character Sets Tab You use the options on the Character Sets tab to configure the character sets you will use within your database (see Figure 2.22). You will determine the database character set, the national character set, the default language, and the default date format. Specifying a database character set defines the type of encoding scheme that Oracle uses to determine how characters are displayed and stored within your Oracle environment. The char- acter set you choose determines the languages that can be represented in your environment. It also controls other nuances such as how your database interacts with your operating system and how much storage is required for your data. The default character set is based on the language setting of the operating system. Specifying a national character set defines how your database represents unicode characters in a database that does not use a Unicode-enabled character set. You use the Default Language setting to manage certain aspects of how your database rep- resents information pertaining to different locales. For example, this setting determines how your database displays time and monetary values. You use the Default Date setting to specify how Oracle displays dates by default. For example, the AMERICA setting shows dates in the DD-MON-YYYY format by default. The Connection Mode Tab You use the options on the Connection Mode tab to specify the type of connections to use for this database (see Figure 2.23). You can choose dedicated or shared server mode. The default connection mode is dedicated server. 4367.book Page 101 Wednesday, October 13, 2004 1:18 PM 102 Chapter 2  Creating and Controlling a Database FIGURE 2.22 The Character Sets tab in the Initialization Parameters screen FIGURE 2.23 The Connection Mode tab on the Initialization Parameters screen Connection types are covered in more detail in Chapter 4, “Oracle Net Services.” 4367.book Page 102 Wednesday, October 13, 2004 1:18 PM Using the Oracle Database Configuration Assistant 103 After completing the Initialization Parameters screen, click Next. You will then be presented with the Database Storage screen. Database Storage The Database Storage screen provides you with the opportunity to review and change the loca- tions of the actual objects that compose the Oracle database, namely, the datafiles, control files, and redo logs (see Figure 2.24). This screen displays a tree structure in the left pane. You can click the various elements within the tree to expand and display the details of each component. Selecting an element displays details about the element in the pane on the right. For example, clicking Controlfile displays a summary of the control filenames and locations in the right pane. You can make manual changes to the names and locations of the control files in the right pane. If you are creating a custom database definition that does not use a template, you can add new objects to a particular group. For example, clicking the Redo Logs folder and then clicking Create lets you add redo log groups to your database definition. If you selected a database tem- plate that included datafile definitions, you cannot add or remove datafiles, tablespaces, or roll- back segments, but you can modify the location of the datafiles, control files, and redo log groups. As with many of the other screens in the DBCA, you can click the File Location Vari- ables button to display the settings for the various Oracle file location parameters, such as the ORACLE_BASE and ORACLE_HOME settings. After completing the Database Storage screen, click Next to create your database. FIGURE 2.24 The DBCA Database Storage screen 4367.book Page 103 Wednesday, October 13, 2004 1:18 PM 104 Chapter 2  Creating and Controlling a Database Creation Options The Creation Options screen (see Figure 2.25) provides you with two options: Create Database Use this option to have the DBCA immediately create your database. Save as a Database Template You actually have two choices with this option. You can elect to save your database definition to a template and create the database at a later time or you can have the DBCA create the template and immediately create your database. If you elect to create your database immediately, the DBCA uses the information you have provided in the previous screens to create all the necessary components of your database, pop- ulate the database with sample schemas if they were chosen, start your database, and allow you to configure the network components of your database such as the Oracle Net listener. We will discuss the listener component in more detail in Chapter 4. If you elect to save your database to a template definition, this definition is added to the list of database definitions that you can select on subsequent executions of the DBCA. You can also let the DBCA create a set of scripts that you can run manually to create the database. FIGURE 2.25 The DBCA Creation Options screen 4367.book Page 104 Wednesday, October 13, 2004 1:18 PM [...]... This simplifies the cloning of databases Oracle uses parameter initialization files to store information about initialization parameters used when an Oracle instance starts Oracle reads the parameter file to obtain information about how the Oracle instance should be sized and configured upon startup The parameter file can be either a plain text file, commonly referred to as a PFILE, or a binary file... Initialization Parameters, you will see a list of all the parameters that can be modified (see Figure 2.29) 110 Chapter 2 FIGURE 2.29 Creating and Controlling a Database The EM Database Control Initialization Parameters screen Parameter initialization files were described in Chapter 1, “Installing Oracle 10g. ” You will see examples of how this is done later in this chapter The Initialization Parameters screen... PFILE and SPFILE parameter files is $ORACLE_ HOME/dbs on Unix systems and %ORACLE_ HOME%/database on Windows systems Oracle uses a search hierarchy when a startup command is issued without specifying either a PFILE or an SPFILE Oracle first looks for a parameter file called spfile $ORACLE_ SID.ora If it doesn’t find that, it searches for spfile.ora Finally it searches for a traditional text PFILE with the default... following a series of screens that are similar to those used to create a database These screens allow you to configure the various aspects of the template, including initialization parameters and datafile and redo log locations Deleting Template Definitions Using the DBCA You can also delete an existing template definition In the Operations screen (see Figure 2.6, shown earlier in this chapter), click... Configuration Assistant (DBCA) to create databases You can choose from preexisting database definitions stored as XML templates or create a database definition from scratch All aspects of the database, including database name, file location, sizing, and initialization parameter settings, are defined within the DBCA You can create a database after completing the database definition, or you can save the definition... proceed with the shutdown process Because Oracle waits until all users are disconnected before shutting down, you can find yourself waiting indefinitely for a client who may be connected but is no longer doing any work or may have left for the day This can require extra work, identifying which connections are still active and either notifying the users to disconnect or forcing the client disconnections... Oracle Internet Directory Service if you elect to use centralized naming and your listener Also, depending on your operating system, you will have to configure or modify the ORATAB file on Unix or create a service in the Windows environment If you elect to have the DBCA create the database immediately, click Finish You will see the Confirmation screen that summarizes the database configuration options... Enterprise Edition Release 10.1.0.2.0 - Production With the Partitioning, OLAP and Data Mining options SQL> shutdown immediate Database closed Database dismounted ORACLE instance shut down SQL> If you are running in a Windows environment and shut down the database using either the Database Control or SQL*Plus tools, the Oracle Service will continue to run Even though the Oracle Windows service is running,... Which of the following commands do you use? A isqlplus startup B isqlplusctl startup C isqlplusctl start D sqlplus start 2 You need to find the directory where the Oracle alert log is being written Which initialization parameter contains this information? A ALERT_LOG_DEST B BACKGROUND_DUMP_DEST C LOG_DESTINATION D INIT_LOG_DUMP_DEST 3 An Oracle application server is an example of what component in... when using this facility The Oracle Enterprise Manager 10g Database Control allows you to monitor and administer a single Oracle database instance or a single Real Application Cluster (RAC) environment The Database Control agent needs to be started when using this facility The Application Server Control is a web-based component of Enterprise Manager used to monitor the Oracle Application Server 10g (9.0.4) . Control Initialization Parameters screen Parameter initialization files were described in Chapter 1, “Installing Oracle 10g. ” You will see examples of how this is done later in this chapter. The Initialization. tool to modify existing database parameters, navigate to the Administration menu. In the Instance section, you can modify your initialization parameters. If you choose All Initialization Parameters,. 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