Week 2Lecture 1

Creating an Oracle Instance

Learning Objectives

Learn the steps for creating a database Understand the prerequisites for creating a

database Configure initial settings for database

creation Create, start, and stop a database

instance

Steps for Creating a Database

Steps in a nutshell:

1. Install Oracle software

2. Create appropriate users (Unix only)

3. Confirm memory and disk storage availability

4. Choose file management, DBA authentication, and initialization parameters

5. Create the database (manual or automated)

6. Test the database (start up and shut down)

Overview of Prerequisites for Creating a Database See your Installation Guide for exact details.

Example of Windows 2000 requirements:

RAM: 128 Megabytes

Virtual Memory: 200 Megabytes

Temp space: 400 Megabytes

Storage:

ORACLE_HOME: 4.5 Gigabytes

System drive: 140 Megabytes

Configuring Initial Settings

Three configuration decisions that must be done prior to creating the database:

Choose DBA authentication method

Choose file management method

Set initialization parameters

DBA Authentication Method

Primarily used to authenticate users who log in with the SYSDBA or SYSOPER roles

Important due to the capabilities of users with these roles

Operating system authentication method can be used for other Oracle users

Password file authentication method can only be used for users with SYSDBA or SYSOPER role assigned

Operating System AuthenticationType of DBA Authentication (first of two methods)

Pros:

Users log on without specifying additional password or user name

Best when only local access or secured line access are allowed

Cons:

Can be a security risk if used with non-secure internet or network lines

Requires knowledge of operating system security

Operating System AuthenticationHow to implement:

Create operating system user for DBA use

Create OSDBA group (UNIX only because Windows automatically creates the group)

Assign operating system user to OSDBA group

Set REMOTE_LOGIN_PASSWORDFILE = NONE

Set OS_AUTHENT_PREFIX as desired

Create Oracle user with same name or name with prefix

Password File AuthenticationType of DBA Authentication (second of two methods)

Pros:

Users must know their Oracle username and password to log onto the database

Best for non-secured line access, such as Internet, is allowed

Cons:

Users required to remember multiple usernames and passwords

Possible security risk due to storage of passwords in an encrypted operating system file

Password File AuthenticationHow to implement: Set REMOTE_LOGIN_PASSWORDFILE = EXCLUSIVE (or SHARE if

database is part of distributed system)

Create password file using the orapwd utility

SYSTEM user is ready at this point

Add more SYSDBA or SYSOPER users by: Creating new Oracle user

Assigning SYSDBA or SYSOPER role to the user

Password file is automatically updated when new users are assigned these roles and when any of these users change their passwords

Set OS_AUTHENT_PREFIX as desired

Create Oracle user with same name or name with prefix

File Management Methods

Files controlled by the file management method are control files, data files, and redo log files

Determines how files are located to help with:

Multiplexing of control and redo log files

I/O load balancing

Determines how files are added, extended, or deleted

User-Managed File ManagementType of File Management (first of two methods)

Pros:

DBA has complete control of names, locations, and sizes of all files

Compatible with older versions

Cons:

DBA must manually delete files after their associated tablespace is dropped

DBA must monitor and adjust file sizes over time

User-Managed File ManagementHow to implement:

For user-managed control files, set CONTROL_FILES to a list of files. For example:

For user-managed redo log files, use the LOGFILE clause in the CREATE DATABASE command.

For user-managed data files, use the DATAFILE clause in the CREATE DATABSE command or the CREATE TABLESPACE command

User-Managed File Management

Example

Initialization parameter:CONTROL_FILES = (/d1/oracle/control01.ctl, /d2/oracle/control02.ctl)

CREATE DATABASE command:CREATE DATABASE TECHNO92

MAXDATAFILES 100

DATAFILE ‘C:\ora\oradata\system01.dbf' SIZE 325M

AUTOEXTEND ON NEXT 10240K MAXSIZE UNLIMITED

LOGFILE GROUP 1 (‘C:\ora\oralogs\redo01.log') SIZE 50M,

GROUP 2 (‘D:\ora\oralogs\redo02.log') SIZE 50M;

Oracle Managed File Management

Type of File Management (second of two methods)

Pros: Automated control of control of names and sizes of all files

DBA only has to determine the locations

Less monitoring required due to automated size adjustment and deleting of appropriate files

Cons: File names can be somewhat cryptic

No control over exact sizes and names of files

Oracle Managed File Management

How to implement:

For Oracle-managed data files, set the DB_CREATE_FILE_DEST to a valid directory

For Oracle-managed control files and redo log files, set DB_CREATE_ONLINE_LOG_DEST_n to a valid directory

Oracle Managed File Management

Example

Initialization parameters:

DB_CREATE_FILE_DEST = ‘C:\ora\oradata'

DB_CREATE_ONLINE_LOG_DEST_1= ‘C:\ora\oralogs’

DB_CREATE_ONLINE_LOG_DEST_2= ‘D:\ora\oralogs’

CREATE DATABASE command:

CREATE DATABASE TECHNO92

MAXDATAFILES 100;

Set the Initialization Parameters Stored in a file named init<sid>.ora prior to

creating the database (<sid> = database name)

The init<sid>.ora is used for many purposes:

Tune memory

Limit the number of users

Set the location of files

Determine how to handle of SQL parsing

Much more

Set the Initialization Parameters

Initial setting

Alternate settings (comments)

Set the Initialization Parameters Important initialization parameters to set

prior to creating a database

DB_BLOCK_SIZE

DB_NAME

DB_DOMAIN

COMPATIBLE

Parameters mentioned in previous slides

Creating a Database

Two distinct methods:

Automated: Database Configuration Assistant

• Better for novice DBA

• Easier to use due to the many pre-defined settings

Manual: CREATE DATABASE command

• More flexible

• Useful when using script for creating multiple identical (or similar) databases on several sites

Create a New Database Using the Database Configuration Assistant

Create a New Database Using the Database Configuration Assistant

The SYS and SYSTEM users must have secure passwords to prevent unauthorized access

Starting and Stopping the Database with Instance Manager

Before going to the console, create an Oracle Net connection for the new database using Net Manager

Starting and Stopping the Database with Instance Manager

When logging into the database in the console, select “SYSDBA” in the Connect as box so you have authority to start or stop the database

Starting and Stopping the Database with Instance Manager

Click this button to begin the shutdown process

Creating a Database Manually

Highlights include these steps:

Create three directories in which files are to be stored:

newlog – for redo log files and control files

newdata – for data files

newadmin – for the init<sid>.ora file and scripts used to create the database

Creating a Database Manually

Create a password file using the orapwd utility from a command line:

orapwd file=“<Z:\zzz>\database\pwdtrial02.ora” password=change_on_install entries=5

Replace <Z:\zzz> with the actual directory path of ORACLE_HOME before typing the command

Creating a Database Manually

Create a Windows service for the database instance from a command line:

oradim –new –sid trial02 –startmode a –pfile <X:\xxx>\newadmin\inittrial02.ora

Replace <X:\xxx> with the actual directory path of root directory for the three new directories

This is only needed in Windows, not in UNIX

Creating a Database Manually

Prepare a CREATE DATABASE statement:CREATE DATABASE <databasename>

MAXDATAFILES <n>

MAXINSTANCES <n>

MAXLOGFILES <n>

MAXLOGMEMBERS <n>

DATAFILE '<path>/<datafilename>' <storage_settings>

UNDO TABLESPACE <undo> DATAFILE '<path>/<file>‘ <storage>

CHARACTER SET <charsetname>

NATIONAL CHARACTER SET <ncharsetname>

LOGFILE GROUP <n> ('<path>/<file>','<path>/<file>', ...)

GROUP <n> ('<path>/<file>','<path>/<file>', ...);

Creating a Database Manually

After running the CREATE DATABSE command, follow up with these steps:

Create TEMP and USERS tablespaces

Create the data dictionary views

Create the PL/SQL packages

Register the database in Windows

Starting and Stopping the Database Manually

Use SQL*Plus from a command line

Start SQL*Plus and log on as SYS:sqlplus /nolog

CONNECT SYS/change_on_install AS SYSDBA

Shut down the database:

SHUTDOWN IMMEDIATE

Start up the database:

STARTUP PFILE=<X:\xxx>\newadmin\inittrial02.ora

Lecture Summary

Installing the Oracle software (if needed) is the first step in creating a new database

Databases can be created manually or by using the Database Configuration Assistant

The DBA authentication method can be either Operating System authentication or password file authentication

File management involves determining the location, name and size of files

Lecture Summary

User-managed file management gives the DBA complete control but requires more monitoring and manual changes

Oracle-managed file (OMF) management automates names, sizes, and tuning of files

Some initialization parameters never change after the database is created

Other initialization parameters can be changed later

Lecture Summary

Database Configuration Assistant provides selections among many default settings for the new database

The new database must have an Oracle Net connection defined prior to accessing it in the console

The Instance Manager can be used to shut down or start up the database

You must be logged on with SYSDBA authority to start or stop the database

Creating a database manually means using the CREATE DATABASE command

A new database service starts up a new database instance in Windows

Lecture Summary

After creating the database manually:

Add tablespaces for users and temporary storage

Add the data dictionary and PL/SQL packages

Add the database to the Windows registry

Use SQL*Plus to shut down or start up a database