Wednesday, September 5, 2007

The Oracle Database 10g preinstall process

The Oracle Database 10g preinstall process

Learning objective

After completing this topic, you should be able to identify the components involved in the Oracle preinstall process.

1. Minimum system requirements

Before you can install Oracle Database 10g, you must ensure that your system has everything it needs to launch the software successfully.

The minimum system requirements for installing Oracle Database 10g across all platforms are

  • 512 MB of physical random access memory (RAM)
  • 1 GB of swap space (or virtual memory)
  • 400 MB of disk space in the temporary director (/tmp or \Temp)
  • 1.5 GB of disk space for the Oracle software
  • 1.5 GB of disk space for the preconfigured database
  • operating-system requirements covered in specific Oracle documentation

You should remember that these requirements are the minimum, and your installation may require more system resources - particularly disk space or RAM.

You should always ensure that your particular installation has enough swap space or virtual memory.

For instance, a system with 2 GB or more of RAM will require a swap space of between one and two times the size of RAM.

Each type of operating system has its own requirements, which are set out in the appropriate Oracle documentation.

You should refer to this information to establish the exact requirements of your particular system.

The documentation provides you with a list of the operating-system releases that Oracle Database 10g supports and a set of instructions for installing OS groups or users.

Before the Oracle Universal Installer interface is launched, Oracle performs several self-tests to ensure your system meets the minimum system requirements.

If your system fails to meet one or more requirements, you can choose to ignore the error and resume the installation. To do this, you run the installer using the –ignoreSysPrereqs flag.

However, if the system requirements aren't met, the chances of a successful installation are greatly reduced.

Question

Which are minimum requirements for a successful Oracle Database 10g install?

Options:

  1. 1 GB of swap space

  2. 1.5 GB of disk space for the Oracle software
  3. 500 MB of disk space in the temporary directory
    (/tmp or \Temp)
  4. 512 MB of physical random access memory (RAM)
  5. 2.5 GB of disk space for the preconfigured database

Answer

For a successful Oracle Database 10g install, minimum system requirements include 1 GB of swap space, 1.5 GB of disk space for the Oracle software, and 512 MB of physical random access memory (RAM).

Option 1 is correct. On systems with 2 GB or more of RAM, the swap space must be between one and two times the size of RAM.

Option 2 is correct. However, some installations may require more disk space.

Option 3 is incorrect. The minimum disk space in the temporary directory is 400 MB.

Option 4 is correct. However, it's best for your installation to have as much RAM as possible.

Option 5 is incorrect. The minimum disk space required for the preconfigured database is 1.5 GB.

2. Using Optimal Flexible Architecture (OFA)

Optimal Flexible Architecture (OFA) is Oracle's recommended standard database architecture.

The OFA standard is a set of configuration guidelines created to ensure reliable Oracle installations that require little maintenance.

This architecture includes a default directory tree and a default file-naming convention.

The OFA naming convention and directory distribution organizes files according to their type and usage, making it easier for you to distinguish between file types.

OFA allows you to distribute database files and Oracle components across multiple disks.

You can use this feature to distribute data files between disks, or to separate control files and log files from data files.

This can help improve system performance. For example, if you place data files and log files on separate disks, the disk heads don't need to move from data sectors to log sectors and back.

OFA is designed to perform the following tasks:

  • eliminate fragmentation of free space
  • facilitate routine administrative tasks
  • facilitate the administration of multiple Oracle databases
  • manage and administer database growth
  • organize large amounts of software

eliminate fragmentation of free space
Using OFA, you can eliminate the fragmentation of free space in the data dictionary, isolate other fragmentation, and minimize resource contention.
facilitate routine administrative tasks
Using OFA, you can facilitate routine administrative tasks like software and data backup, to avoid data corruption.
facilitate the administration of multiple Oracle databases
Using OFA, you can administer multiple Oracle homes optimally, because you can store the files for each Oracle home on a separate disk or in a separate partition.
manage and administer database growth
Using OFA, you can manage and administer database growth by distributing storage between multiple disks.
organize large amounts of software

Using OFA, you can organize large amounts of complicated software and data on disk, which helps prevent device bottlenecks and slowed performance.

The flexible, distributed architecture of OFA allows you to add users, data files, tables, and indexes wherever necessary, with minimum inconvenience.

For example, you can place different databases on separate drives, leaving plenty of space for expansion on each drive.

An example of an OFA directory tree is shown.

Question

What do you think are the advantages of using OFA?

Options:

  1. Easier administration of multiple Oracle homes

  2. Easier file identification
  3. Improved performance
  4. Reduced storage space requirements

Answer

Using OFA improves performance, and it makes it easier for you to identify files and administer multiple Oracle homes.

Using OFA, you can administer multiple Oracle homes optimally because you can store the files for each Oracle home on a separate disk or in a separate partition.

Using OFA's default filenames, you can easily distinguish between the different types of Oracle files. For example, you can easily tell the difference between a log file, a control file, and a data file.

Using OFA, you can improve performance by placing data files and log files on separate disks. In this way, the disk heads don't need to keep moving from data sectors to log sectors and back.

Using OFA has no effect on data compression, so it doesn't reduce storage space requirements. However, it does let you distribute storage between multiple disks.

OFA's naming strategy helps to maintain an orderly directory tree, ease recognition of OFA resources, and avoid naming collisions.

The naming standard provides a different OFA syntax for the mount point directories, the subdirectories on those mount points, and the actual database files.

The different types of OFA syntax include

  • mount point syntax
  • home directories syntax
  • software directories syntax
  • subdirectories syntax
  • file-naming syntax
mount point syntax
The mount point syntax names all mount points using the syntax /pm. Here p is a string constant and m is a unique fixed-length key that differentiates mount points. The syntax m is generally a two-digit number. For example, you can name a mount point /u01 or /disk01.
home directories syntax
The home directories syntax names all home directories using the syntax /pm/h/u. Here pm is a mount point name, h is a standard directory name, and u is the name of the directory owner. For example, you can name a home directory /u01/app/oracle or /u01/home/oracle.
software directories syntax
The software directories syntax helps OFA to execute multiple versions of application software simultaneously . The syntax stores all versions of the Oracle software in a directory using the syntax, /pm/h/u/product/v. Here pm is a mount point name, h is a standard directory name, and u is the name of the directory owner. In this syntax, product is a literal and the variable v is the version number. For example, you can name an installation of the Oracle Database 10g version 10.2.0, /u01/app/oracle/product/10.2.0.
subdirectories syntax
The subdirectories syntax enables the OFA to organize administrative data. The syntax stores database-specific administration files in subdirectories using the syntax /h/admin/d/a/. Here h is the home directory of the Oracle software owner, admin is a literal, d is the database name, and a is a subdirectory for each database administration file. For example, you can name a subdirectory containing SQL files /u01/admin/oracle/adhoc.
file-naming syntax
The file-naming syntax enables you to identify database files easily. The syntax is /pm/q/d/f. Here p is a string constant, m is a unique fixed-length key that distinguishes mount points, q is a string distinguishing Oracle data from all other files, d is a database name, and f is the filename. For example, you can name database files as follows:

  • a control file - /pm/q/d/controln.ctl
  • a redo log file - /pm/q/d/redon.log
  • a data file - /pm/q/d/tn.dbf

Question

Match each OFA component to the correct naming convention.

Options:

  1. Mount points
  2. Home directories
  3. Subdirectories
  4. Control files

Targets:

  1. /h/admin/d/a/
  2. /pm/q/d/f
  3. /pm
  4. /pm/h/u

Answer

For mount points the naming convention is /pm, for home directories it's /pm/h/u, for control files it's /pm/q/d/f, and for subdirectories it's /h/admin/d/a/.

An example of an OFA-compliant mount point is /u01.

An example of an OFA-compliant home directory is /u01/home/oracle.

An example of an OFA-compliant subdirectory is /u01/admin/oracle/arch.

An example of an OFA-compliant control file is /u01/q/oracle/control05.ctl.

3. Environment variables

Environment variables are a series of hidden values that the web server sends to every program you run. To avoid complications when running Oracle, there are some environment variables you should set in advance of an installation. The following Oracle environment variables are vital to a successful Oracle install.

  • NLS_LANG
  • ORACLE_BASE
  • ORACLE_HOME
  • ORACLE_SID
NLS_LANG

ORACLE_BASE

ORACLE_HOME

ORACLE_SID

Question

Match each environment variable to the appropriate functionality.

Options:

  1. ORACLE_BASE
  2. ORACLE_HOME
  3. ORACLE_SID
  4. NLS_LANG

Targets:

  1. Specifies the initial instance name
  2. Specifies the initial NLS settings for a session using the format
    language_territory.characterset
  3. Specifies the directory containing the Oracle software
  4. Facilitates future installations and upgrades

Answer

ORACLE_BASE facilitates future installations and upgrades and ORACLE_HOME specifies the directory containing the Oracle software. ORACLE_SID specifies the initial instance name and NLS_LANG specifies the initial NLS settings for a session.

You use ORACLE_BASE to specify the base of the Oracle directory structure for OFA.

This environmental variable is a directory path - for instance, $ORACLE_BASE/product/10.1.0.

This environmental variable is a string of numbers and letters that must begin with a letter.

An example of the NLS_LANG environmental variable is AMERICAN_DENMARK.WE8MSWIN1252.

Summary

To install Oracle successfully, you must ensure that your system meets the minimum system requirements. To establish the requirements of your particular operating system, you should use the accompanying Oracle documentation.

Optimal Flexible Architecture (OFA) is Oracle's recommended standard architecture, including a default file-naming convention and a default directory layout. An OFA-compliant installation of Oracle offers optimal flexibility and scalability.

Environment variables that are vital to Oracle installations include ORACLE_BASE, ORACLE_HOME, ORACLE_SID, and NLS_LANG. Setting these before installation may help avoid future problems.

1 comment:

Blogger said...

BlueHost is definitely one of the best web-hosting provider for any hosting services you require.