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
Trang 1database 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
Trang 2After 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
Figure 2-6 The Windows service defining an Oracle instance
Trang 3on 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
Trang 4TIP 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
Trang 5Post-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
Trang 6The 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
Trang 7Plan 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
Trang 82 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.)
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
Trang 98 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
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
Trang 1014 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