OCA/OCP Oracle Database 11g All-in-One Exam Guide 86 database controlfile. At this stage, the controlfile does not exist; this parameter will tell the instance where to create it. Some of the other parameters are self-explanatory and can be easily related back to the options taken when going through the steps of the exercise, but eventually you must refer to the Oracle Documentation Library (the volume you need is titled “Reference”) and read up on all of them. All! Those necessary for examination purposes will be described at the appropriate point. EXAM TIP What is the only instance parameter for which there is no default? It is DB_NAME. A parameter file must exist with at least this one parameter, or you cannot start an instance. The DB_NAME can be up to eight characters long, letters and digits only, beginning with a letter. The Database Creation Shell Script This is the file the DBCA executes to launch the database creation process. It is a batch file on Windows, and a shell script on Linux. A Windows example: mkdir D:\oracle\app mkdir D:\oracle\app\admin\ocp11g\adump mkdir D:\oracle\app\admin\ocp11g\dpdump mkdir D:\oracle\app\admin\ocp11g\pfile mkdir D:\oracle\app\cfgtoollogs\dbca\ocp11g mkdir D:\oracle\app\flash_recovery_area mkdir D:\oracle\app\oradata\ocp11g mkdir D:\oracle\app\product\11.1.0\db_3\database set ORACLE_SID=ocp11g set PATH=%ORACLE_HOME%\bin;%PATH% D:\oracle\app\product\11.1.0\db_3\bin\oradim.exe -new -sid OCP11G -startmode manual -spfile D:\oracle\app\product\11.1.0\db_3\bin\oradim.exe -edit -sid OCP11G -startmode auto -srvcstart system D:\oracle\app\product\11.1.0\db_3\bin\sqlplus /nolog @D:\oracle\app\admin\db11g\scripts\ocp11g.sql First, the script creates a few directories in the Oracle Base. Then it sets the ORACLE_SID environment variable (more of this later) and prepends the ORACLE_ HOME/bin directory to the search path. The two commands that use oradim.exe will not appear on a Linux system. On Windows, an Oracle instance runs as a Windows service. This service must be created. The oradim.exe utility is run twice. The first time will define a new service in the Windows registry, with the system identifier OCP11G, and put the service on manual start. The -spfile switch refers to the type of initialization parameter file to be used. The second use of oradim.exe edits the service, to set it to start automatically whenever Windows starts. Figure 2-6 shows the resulting service defined in the registry. To see this, use the regedit.exe registry editor (or some similar tool) to navigate to the key HKEY_LOCAL_MACHINE/SYSTEM/currentControlSet/Services/OracleServiceOCP11G Each database instance that can run on a Windows machine will be a service, named after the name of the instance (in this case, OCP11G) that was provided in Exercise 2-4, Step 7. Chapter 2: Installing and Creating a Database 87 PART I After the service creation, the script launches SQL*Plus and runs the SQL script ocp11g.sql which will control the creation of the database: set verify off PROMPT specify a password for sys as parameter 1; DEFINE sysPassword = &1 PROMPT specify a password for system as parameter 2; DEFINE systemPassword = &2 PROMPT specify a password for sysman as parameter 3; DEFINE sysmanPassword = &3 PROMPT specify a password for dbsnmp as parameter 4; DEFINE dbsnmpPassword = &4 host D:\oracle\app\product\11.1.0\db_3\bin\orapwd.exe file=D:\oracle\app\product\11.1.0\db_3\database\PWDocp11g.ora password=&&sysPassword force=y @D:\oracle\app\admin\ocp11g\scripts\CreateDB.sql @D:\oracle\app\admin\ocp11g\scripts\CreateDBFiles.sql @D:\oracle\app\admin\ocp11g\scripts\CreateDBCatalog.sql @D:\oracle\app\admin\ocp11g\scripts\emRepository.sql @D:\oracle\app\admin\ocp11g\scripts\postDBCreation.sql At the top of the script, there are prompts for passwords for four critical accounts. These will be provided by the password entered in Exercise 2-4, Step 9. Then, using host to spawn an operating system shell, the script runs the orapwd .exe utility (just called orapwd on Linux.) This will create an external password file for the database. The name of the file must be %ORACLE_HOME%\database\PWD<db_name>.ora on Windows, or $ORACLE_HOME/dbs/orapw<db_name> Figure 2-6 The Windows service defining an Oracle instance OCA/OCP Oracle Database 11g All-in-One Exam Guide 88 on Linux, where <db_name> is the name of the database. This is the name provided for the global database name in Exercise 2-4, Step 7, but without any domain suffix. Usually, this is the same as the instance name—but they are not the same thing. The script then calls CreateDB.sql, which will actually create the database. The CREATE DATABASE Command This is an example of the CreateDB.sql script: connect "SYS"/"&&sysPassword" as SYSDBA set echo on spool D:\oracle\app\admin\ocp11g\scripts\CreateDB.log startup nomount pfile="D:\oracle\app\admin\ocp11g\scripts\init.ora"; CREATE DATABASE "ocp11g" MAXINSTANCES 8 MAXLOGHISTORY 1 MAXLOGFILES 16 MAXLOGMEMBERS 3 MAXDATAFILES 100 DATAFILE 'D:\oracle\app\oradata\ocp11g\system01.dbf' SIZE 300M REUSE AUTOEXTEND ON NEXT 10240K MAXSIZE UNLIMITED EXTENT MANAGEMENT LOCAL SYSAUX DATAFILE 'D:\oracle\app\oradata\ocp11g\sysaux01.dbf' SIZE 120M REUSE AUTOEXTEND ON NEXT 10240K MAXSIZE UNLIMITED SMALLFILE DEFAULT TEMPORARY TABLESPACE TEMP TEMPFILE 'D:\oracle\app\oradata\ocp11g\temp01.dbf' SIZE 20M REUSE AUTOEXTEND ON NEXT 640K MAXSIZE UNLIMITED SMALLFILE UNDO TABLESPACE "UNDOTBS1" DATAFILE 'D:\oracle\app\oradata\ocp11g\undotbs01.dbf' SIZE 200M REUSE AUTOEXTEND ON NEXT 5120K MAXSIZE UNLIMITED CHARACTER SET WE8MSWIN1252 NATIONAL CHARACTER SET AL16UTF16 LOGFILE GROUP 1 ('D:\oracle\app\oradata\ocp11g\redo01.log') SIZE 51200K, GROUP 2 ('D:\oracle\app\oradata\ocp11g\redo02.log') SIZE 51200K, GROUP 3 ('D:\oracle\app\oradata\ocp11g\redo03.log') SIZE 51200K USER SYS IDENTIFIED BY "&&sysPassword" USER SYSTEM IDENTIFIED BY "&&systemPassword"; spool off The script connects to the instance, using the syntax for password file authentication (this is fully described in Chapter 3). Let’s consider the script line by line. The echo and spool commands cause SQL*Plus to write out a log of everything that happens next. The STARTUP NOMOUNT command builds the instance in memory, using the static parameter file we saw earlier. The significance of “NOMOUNT” will be dealt with in Chapter 3; for now, let it suffice that it is necessary, as there is no database to mount and open. After this completes, there will be an instance running with an SGA and the background processes. The SGA will have been sized according to the parameters in the nominated init.ora file. The CREATE DATABASE command, which continues to the semicolon at the end of the file, is followed by the database name (which is ocp11g). The first section of the command sets some overall limits for the database. These can all be changed subsequently, but if they are clearly inappropriate, it is a good idea to change them now, before creation. Chapter 2: Installing and Creating a Database 89 PART I TIP With the current release, some of these limits (such as the number of datafiles) are only soft limits, and therefore of little significance. Datafile specifications are provided for the SYSTEM, SYSAUX, and UNDO tablespaces. Tempfile specifications for a TEMPORARY tablespace are also provided. The database character set used for storing data dictionary data and table columns of type VARCHAR2, CHAR, and CLOB is specified followed by the national character set (which is used for columns of type NVARCHAR2, NCHAR, and NCLOB). It is possible to change the character set after creation with SQL*Plus. Choice and use of character sets, and other aspects of globalization, are covered in detail in Chapter 26. TIP Until version 9i of the database, there was no supported means for changing the database character set after creation: it was therefore vital to get this right. With 9i and later, it is possible to change it afterward, but this is not an operation to embark on lightly. Get it right now! The logfile clause specifies three log file groups, each consisting of one member. This is an example of the DBCA defaults perhaps not doing a perfect job. It would be better practice to multiplex the redo log: to create at least two members for each group. Not a problem—this can be fixed later (in Chapter 14). The online redo log will always require substantial tuning; the defaults are applicable to virtually no production systems. Finally, SYS and SYSTEM passwords are initialized, and spooling to the log is switched off. This one file with the CREATE DATABASE command will create a database. After its successful execution, you will have an instance running in memory, and a database consisting of a controlfile and copies as specified by the CONTROL_FILES initialization parameter, and the datafiles and redo logs specified in the CREATE DATABASE command. A data dictionary will have been generated in the SYSTEM tablespace. But although the database has been created, it is unusable. The remaining scripts called by ocp11g.sql make the database usable. The CREATE DATABASE command has many options, all of which have defaults. For example, if you do not specify a datafile for the SYSTEM or SYSAUX tablespace, one will be created anyway. If you do not specify a character set, there is a default, which will depend on the operating system configuration (it may not be a very helpful default—commonly, it is US7ASCII, which is inadequate for many applications). There are also defaults for the online redo logfiles. There are no defaults for the TEMP and UNDO tablespaces; if these are not specified, the database will be created without them. Not a problem—they can be added later. TIP The CREATE DATABASE command can be extremely long and complicated—but there are defaults for everything. You can create a database from a SQL*Plus prompt with two words: CREATE DATABASE. OCA/OCP Oracle Database 11g All-in-One Exam Guide 90 Post-Creation Scripts The other SQL scripts called by ocp11g.sql to complete the database creation will depend on the options chosen when going through the DBCA. In this example, as all options except for Enterprise Manager Database control were deselected, there are only four: • CreateDBfiles.sql This is of minor significance. It creates a small tablespace, USERS, to be used as the default location for any objects created by users. • CreateDBCatalog.sql This is vital. It runs a set of scripts in the $ORACLE_HOME/rdbms/admin directory that construct views on the data dictionary and create many PL/SQL packages. It is these views and packages that make it possible to manage an Oracle database. • emRepository.sql This runs the script to create the objects needed by Enterprise Manager Database Control. It is run because this was selected in Exercise 2-4, Step 8. • postDBCreation.sql This generates a server parameter file from the init.ora file (more of this in Chapter 3), unlocks the DBSNMP and SYSMAN accounts used by Enterprise Manager, and runs the Enterprise Manager configuration Assistant (which is emca.bat on Windows, emca on Linux) to configure Database Control for the new database. The DBCA’s Other Functions The opening screen of the DBCA gives you five options: • Create a database • Configure database options • Delete a database • Manage templates • Configure automatic storage management “Configure Database Options” helps you change the configuration of a database you have already created. In the preceding exercise, you deselected all the options: this was to make the creation as quick and simple as possible. TIP By deselecting all the options, particularly those for “standard database components,” creation time is reduced dramatically. If you decide subsequently to install some optional features, such as Java or OLAP, running the DBCA again is the simplest way to do it. An alternative method is to run the scripts to install the options by hand, but these are not always fully documented and it is possible to make mistakes—the DBCA is better. Chapter 2: Installing and Creating a Database 91 PART I The Delete A Database radio button will prompt you for which database you wish to delete, and then give you one more chance to back out before it deletes all the files that make up the database and (for a Windows system) invokes oradim.exe to delete the instance’s service from the Windows registry as well. TIP Behind the scenes, Delete A Database invokes the SQL*Plus command DROP DATABASE. There is some protection for this command: the database cannot be open at the time; it must be in mount mode. Manage Templates allows you to store database creation options for later use. Remember that in the exercise, you chose to create a “Custom” database. A custom database is not preconfigured—you chose it in order to see all the possibilities as you worked your way through the DBCA. But apart from “Custom,” there were options for “Data Warehouse” and “General Purpose or Transaction Processing.” If you choose either of these, the DBCA suggests different defaults with which to create a database. These defaults will be partly optimized for decision support systems (DSS, the data warehouse option) or for online transaction processing systems (OLTP, the transaction processing option). These templates do not create a database from the beginning; they expand a set of compressed datafiles and modify these. The final question when you created your database gave you the possibility of saving it as a template—i.e., not to create it at all, but to save the definition for future use. The DBCA will let you manage templates, either the supplied ones or new templates you create yourself, by creating, copying, modifying, or deleting them. Templates can be extremely useful if you are in a position where you are frequently creating and re- creating databases that are very similar. Finally, the Configure Automatic Storage Management option launches a wizard that will create an ASM instance. An ASM instance does not open a database; it manages a pool of disks, used for database storage. This is covered in Chapter 20. Two-Minute Drill Identify the Tools for Administering an Oracle Database • Installation: the OUI • Database creation and upgrade: DBCA, DBUA • For issuing ad hoc SQL: SQL*Plus, SQL Developer • Backup: RMAN, Oracle Secure Backup • Network administration: Oracle Net Manager, Oracle Net Configuration Assistant • Data load and unload utilities: Data Pump, SQL*Loader • Management: Oracle Enterprise Manager, Database Control, and Grid Control OCA/OCP Oracle Database 11g All-in-One Exam Guide 92 Plan an Oracle Database Installation • Hardware requirements • Disk space • Main memory • Swap space • Temporary space • A graphics terminal • Operating system requirements • Certified version • Necessary packages • Kernel settings • OFA: an appropriate directory for the Oracle Base Install the Oracle Software by Using the Oracle Universal Installer (OUI) • Use a suitable operating system account. • Set necessary environment variables (Linux, Unix). • Provide access to the root account (Linux, Unix). • Make either an interactive or silent install. Create a Database by Using the Database Configuration Assistant • A database can be created with the DBCA or from the SQL*Plus command line. • The DBCA can create a database from a saved template. • The DBCA and SQL*Plus commands can delete a database. • An instance must be created before the database can be created. • Any options not selected at creation time can be added later. Self Test 1. Which of these tools is not usually installed with the Oracle Universal Installer? (Choose the best answer.) A. The Oracle Universal Installer itself B. SQL*Plus C. SQL Developer D. Oracle Enterprise Manager Grid Control Chapter 2: Installing and Creating a Database 93 PART I 2. Which tools can be used to create a database? (Choose three correct answers.) A. Database Configuration Assistant B. Database Upgrade Assistant C. SQL*Plus D. Oracle Universal Installer E. Oracle Enterprise Manager Database Control 3. Oracle provides the ability to back up the entire environment, not just the Oracle Database. What tool can do this? (Choose the best answer.) A. Recovery Manager B. Oracle Secure Backup C. User-managed backups, carried out with operating system commands 4. What statement best describes the relationship between the Oracle Base and the Oracle Home? (Choose the best answer.) A. The Oracle Base exists inside the Oracle Home. B. The Oracle Base can contain Oracle Homes for different products. C. One Oracle Base is required for each product, but versions of the product can exist in their own Oracle Homes within their Oracle Base. D. The Oracle Base is created when you run the orainstRoot.sh script, and contains a pointer to the Oracle Home. 5. What does Optimal Flexible Architecture (OFA) describe? (Choose the best answer.) A. A directory structure B. Distributed database systems C. Multitier processing architecture D. OFA encompasses all the above 6. What environment variable must be set on Linux before running the Oracle Universal Installer? (Choose the best answer.) A. ORACLE_HOME B. ORACLE_BASE C. ORACLE_SID D. DISPLAY 7. If the OUI detects that a prerequisite has not been met, what can you do? (Choose the best answer.) A. You must cancel the installation, fix the problem, and launch OUI again. B. A silent install will fail; an interactive install will continue. C. Instruct the OUI to continue (at your own risk). D. The options will depend on how far into the installation the OUI is when the problem is detected. OCA/OCP Oracle Database 11g All-in-One Exam Guide 94 8. What type of devices can the OUI install an Oracle Home onto? (Choose one or more correct answers.) A. Regular file systems B. Clustered file systems C. Raw devices D. ASM disk groups 9. Which command-line switch can be used to prevent the OUI from stopping when prerequisite tests fail? (Choose the best answer.) A. -silent B. -record C. -responsefile D. -ignoresysprereqs 10. When does an OUI inventory get created? (Choose the best answer.) A. Every time a new Oracle Home is created B. Every time a new Oracle Base is created C. Before the first run of the OUI D. During the first run of the OUI 11. To create a database, in what mode must the instance be? (Choose the best answer.) A. Not started B. Started in NOMOUNT mode C. Started in MOUNT mode D. Started in OPEN mode 12. The SYSAUX tablespace is mandatory. What will happen if you attempt to issue a CREATE DATABASE command that does not specify a datafile for the SYSAUX tablespace? (Choose the best answer.) A. The command will fail. B. The command will succeed, but the database will be inoperable until the SYSAUX tablespace is created. C. A default SYSAUX tablespace and datafile will be created. D. The SYSAUX objects will be created in the SYSTEM tablespace. 13. Is it necessary to have a database listener created before creating a database? (Choose the best answer.) A. No. B. Yes. C. It depends on whether the database is created with the DBCA or SQL*Plus. D. It depends on whether the Database Control option is selected in the DBCA. Chapter 2: Installing and Creating a Database 95 PART I 14. Several actions are necessary to create a database. Place these in the correct order: 1. Create the data dictionary views. 2. Create the parameter file. 3. Create the password file. 4. Issue the CREATE DATABASE command. 5. Issue the STARTUP command. (Choose the best answer.) A. 2, 3, 5, 4, 1 B. 3, 5, 2, 4, 1 C. 5, 3, 4, 2, 1 D. 2, 3, 1, 5, 4 15. What instance parameter cannot be changed after database creation? (Choose the best answer.) A. All instance parameters can be changed after database creation. B. All instance parameters can be changed after database creation, if it is done while the instance is in MOUNT mode. C. CONTROL_FILES. D. DB_BLOCK_SIZE. 16. What files are created by the CREATE DATABASE command? (Choose one or more correct answers.) A. The controlfile B. The dynamic parameter file C. The online redo log files D. The password file E. The static parameter file F. The SYSAUX tablespace datafile G. The SYSTEM tablespace datafile 17. What will happen if you do not run the CATALOG.SQL and CATPROC.SQL scripts after creating a database? (Choose the best answer.) A. It will not be possible to open the database. B. It will not be possible to create any user tables. C. It will not be possible to use PL/SQL. D. It will not be possible to query the data dictionary views. E. It will not be possible to connect as any users other than SYS and SYSTEM. . Control OCA/ OCP Oracle Database 11g All-in-One Exam Guide 92 Plan an Oracle Database Installation • Hardware requirements • Disk space • Main memory • Swap space • Temporary space • A graphics. install. Create a Database by Using the Database Configuration Assistant • A database can be created with the DBCA or from the SQL*Plus command line. • The DBCA can create a database from a saved. Control Chapter 2: Installing and Creating a Database 93 PART I 2. Which tools can be used to create a database? (Choose three correct answers.) A. Database Configuration Assistant B. Database Upgrade