OCA: Oracle Database 11g Administrator Certified Associate Study Guide- P12

OCA: Oracle Database 11g Administrator Certified Associate Study Guide- P12: There is high demand for professionals in the information technology (IT) industry, andOracle certifications are the hottest credential in the database world. You have made theright decision to pursue certification, because being Oracle Database 11g certified will giveyou a distinct advantage in this highly competitive market.
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OCA: Oracle Database 11g Administrator Certified Associate Study Guide- P12 Using DBCA to Create Oracle 11g Databases 481 When the creation process is complete, connect to the database with one of the toolssuch as SQL*Plus or Enterprise Manager to ensure that all the database options andcomponents were installed properly. Logging into Enterprise Manager will give you anoverview of the new database. By using the URL specified in Figure 9.31, you can invokethe Database Control home page. Log in using the SYSMAN account with the password yousupplied in Figure 9.7. Figure 9.33 shows the home screen of Enterprise Manager DatabaseControl.Figure 9.33 Enterprise Manager Database Control home pageConfiguring an Oracle Database Using the DBCAThe DBCA lets you change various aspects of an existing database. To change the databaseconfiguration, select Configure Database Options on the DBCA Operations screen (shownearlier in this chapter in Figure 9.2). If the database is not started, the DBCA starts it foryou automatically. You must connect to the database as a user who has DBA authority.482 Chapter 9 N Creating an Oracle 11g Database Once you have selected and started the database, you can add options that may nothave been previously included in the database. Using DBCA you can perform the followingchanges to database configuration:NÛ Add database components (refer to Figure 9.13).NÛ Change database security settings from pre-11g default security setting to 11g enhanced security settings, or vice versa (refer Figure 9.24).NÛ Change the default connection mode for the database. You can change from dedicated server mode to shared server mode, or vice versa (refer Figure 9.22).Deleting an Oracle Database Using the DBCAYou can also delete a database using the DBCA. On the Operations screen (Figure 9.2),choose Delete a Database, and click Next to open the Database screen. The DBCA lists allthe databases available for deletion. Choose the database you want to delete. If you click Finish, the DBCA removes all files on the disk associated with the databaseyou have chosen. If you are using Windows, the DBCA also removes the service associatedwith the database. Exercise 9.1 shows you how to delete a database manually using SQL*Plus.e x e r C i s e 9 .1Delete or remove an Oracle Database manuallySome DBAs prefer to use a command-line interface to perform their tasks. You can deletea database using the command-line tool SQL*Plus.To do so, first connect to SQL*Plus as an administrator who has the ability to start up thedatabase; that is, an administrator with either the SYSOPER or SYSDBA privilege.Here’s an example:/u01/app/oracle>sqlplus sys/**** as sysdbaOnce you are connected, you need to put the database in MOUNT mode. Issue the followingcommand if the database is not running:Startup mount;Next, issue the following command:Drop database;This command deletes all the files associated with the database. If you are using raw diskdevices, the special files created for these devices are not deleted. Also, you may have toremove any archived logs from the database archive area using the appropriate operating-system command. Using DBCA to Create Oracle 11g Databases 483Managing Database Templates Using the DBCAAs I explained earlier in this chapter, the DBCA can store and use XML-based templates tocreate your Oracle Database. As the DBA, you can manage these database-definition tem-plates. Saving a definition of your database in a template format makes it easier to performvarious tasks. For example, you can copy a preexisting template to modify new databasedefinitions. The template definition is normally stored in the $ORACLE_HOME/assistants/dbca/templates directory on Unix and in the %ORACLE_HOME%assistantsdbca emplatesdirectory on Windows systems. The DBCA can use two types of templates: seed and nonseed. Seed templates are tem-plate definitions that contain database-definition information and the actual data files andredo log files. The advantage of a seed template is that the DBCA makes a copy of the datafiles and redo logs included in the definition file. These prebuilt data files include all schemainformation, which makes for a faster database-creation process. The seed templates carrya .dbc extension. The associated predefined data files are stored as files having a .dfb exten-sion. When you use a seed template, you can change the database name, the data-file locations,the number of control files and redo log groups, and the initialization parameters. Nonseed templates contain custom-defined database definitions. Unlike seed templates,they do not come with preconfigured data files and redo logs. Nonseed templates carry a.dbt extension. N ...