Oracle8i Administrator's Reference
Release 3 (8.1.7) 64 Bit for Fujitsu Siemens ReliantUNIX

Part Number A89874-01
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Optimal Flexible Architecture

This appendix contains information on Optimal Flexible Architecture. It contains the following sections:

Optimal Flexible Architecture

Oracle Corporation recommends that the Optimal Flexible Architecture (OFA) standard be implemented when installing and configuring Oracle8i. The OFA standard is a set of configuration guidelines created to ensure fast, reliable Oracle databases that require little maintenance.

OFA is designed to:

Characteristics of an OFA-Compliant Database

An OFA-compliant database provides the following benefits:

File System Organization

The file system is organized to enable easy administration for issues such as:

Distributed I/O Loads

I/O loads are distributed across enough disk drives to prevent performance bottlenecks.

Hardware Support

In most cases, investment in new hardware is not required to take advantage of the OFA standard.

Safeguards Against Drive Failures

By distributing applications across more than one drive, drive failures affect as few applications as possible.

Distribution of Home Directories

The following items can be distributed across more than one disk drive:

Integrity of Login Home Directories

It is possible to add, move, or delete login home directories without having to revise programs that refer to them.

Independence of UNIX Directory Subtrees

Categories of files are separated into independent UNIX directory subtrees so that files in one category are minimally affected by operations on files in other categories.

Supports Concurrent Execution of Application Software

You can execute multiple versions of application software simultaneously, enabling the user to test and use a new release of an application before abandoning the previous version. Transferring to a new version after an upgrade is simple for the administrator and transparent for the user.

Distinguishes Administrative Information for Each Database

The ability to separate administrative information on one database from that of another ensures a reasonable structure for the organization and storage of administrative data.

Uses Consistent Database File Naming

Database files are named so that:

Separation of Tablespace Contents

Tablespace contents are separated to:

I/O Loads Tuned Across All Drives

I/O loads are tuned across all drives, including drives storing Oracle data in raw devices.

Additional Benefits of OFA for Parallel Server

For Oracle Parallel Server Installations:

Optimal Flexible Architecture Implemented on UNIX

A careful naming strategy for database files eliminates data administration problems. The OFA rules provided here correspond to the original OFA recommendations published in The OFA Standard: Oracle8 for Open Systems.

Mount Points

This section describes the naming conventions for mount points.

Create Mount Points

An installation of Oracle8i requires at least two mount points: one for the software and at least one for the database files. If implementing the recommended OFA, at least four mount points are required: one for the software and at least three for database files.

Mount Point Syntax

Name all mount points using the syntax /pm, where p is a string constant and m is a unique fixed-length key (typically a two-digit number) used to distinguish each mount point. For example: /u01 and /u02, or /disk01 and /disk02.

Naming Mount Points for Very Large Databases (VLDBs)

If each disk drive contains database files from one application and there are enough drives for each database to ensure no I/O bottleneck, then use the syntax /q/dm for naming mount points. Table A-1 describes the variables used in this syntax.

Table A-1 Syntax for Naming Mount Points  
Variable  Description 


A string denoting that Oracle data is stored here 


The value of the initialization parameter DB_NAME (synonymous with the instance sid for single-instance databases) 

For example, mount points named /u01/oradata/test and /u02/oradata/test allocate two drives for the Oracle test database.

Naming Directories

This section describes the naming conventions for OFA compliant directories.

Home Directory Syntax

Name home directories using the syntax /pm/h/u. Table A-2 describes the variables used in this syntax.

Table A-2 Syntax for Naming Home Directories  
Variable  Description 


A mount point name 


A standard directory name 


The name of the owner of the directory 

For example, /u01/app/oracle is the Oracle Server software owner home directory (also referred to as the Oracle base directory and the default used by the Installer) and /u01/app/applmgr is an Oracle applications software owner home directory.

Placing home directories at the same level in the UNIX file system is advantageous because it allows the collection of applications owner login home directories on different mount points to be referred to with the single pattern matching string, /*/app/*.

Referring to Path Names

Refer to explicit path names only in files designed specifically to store them, such as /etc/passwd and the Oracle oratab file. Refer to group memberships only in the /etc/group file.

Software Directories

To help fulfill the OFA feature of simultaneously executing multiple versions of application software, store each version of the Oracle8i Server software in a directory matching the pattern /pm/h/product/v.

Table A-3 describes the variables used in this syntax.

Table A-3 Syntax for Naming Oracle8i Server Software Directories  
Variable  Description 


A mount point name 


A standard directory name 


The version of the software 

For example, /u01/app/oracle/product/ indicates the start of the directory structure where the Oracle8i Server files are located. Set the
ORACLE_HOME environment variable to this directory.

Naming Subdirectories

To facilitate the organization of administrative data, Oracle Corporation recommends that you store database-specific administration files in subdirectories matching the pattern h/admin/d/a/, where h is the Oracle software owner's home directory, d is the database name (DB_NAME), and a is a subdirectory for each of the database administration files. Table A-4 describes the database administration file subdirectories:

Table A-4 Subdirectories for Database Administration Files  
Sub Directory  Description 


Ad hoc SQL scripts for a particular database 


Archived redo log files 


Audit files
(Set AUDIT_FILE_DEST in the configdb_name.ora file to the /adump directory. Clean out this subdirectory periodically). 


Background process trace files 


Core dump files 


Programs used to create the database 


Database export files 


Files recording the status and history of the database 


Instance parameter files 


User SQL trace files 

For example, the subdirectory adhoc would have the following path name, /u01/app/oracle/admin/sab/adhoc/ if it were part of the database named sab.

Naming Database Files

The following naming convention for database files ensures that they are easily identifiable:

Table A-5 describes this syntax:

Table A-5 Syntax for Naming Database Files  
Variable  Description 


A mount point name described previously in this chapter 


A string distinguishing Oracle data from all other files (usually named ORACLE or oradata) 


The DB_NAME of the database 


An Oracle tablespace name 


A two-digit string 


Do not store files other than a control, redo log, or data file associated with database d in the path /pm/q/d

Following this convention, you could produce, for example, a data file with the name /u03/oradata/sab/system01.dbf, making it easy to see to which database the file belongs.

Separate Segments with Different Requirements

Separate groups of segments with different lifespans, I/O request demands, and backup frequencies across different tablespaces.

Table A-6 describes the special tablespaces that you must create for each Oracle database. These tablespaces are in addition to those required for application segments.

Table A-6 Special Tablespaces  
Tablespace  Description 


Data dictionary segments 


Temporary segments 


Rollback segments 


Miscellaneous user segments 


Index associated with data in USERS tablespace 


Oracle interMedia segment 

This method is effective because dictionary segments are never dropped, and no other segments that can be dropped are allowed in the SYSTEM tablespace. This ensures that the SYSTEM tablespace does not require a rebuild due to tablespace free space fragmentation.

Because rollback segments are not stored in tablespaces holding applications data, the administrator is not blocked from taking an application's tablespace offline for maintenance. The segments are partitioned physically by type, and the administrator can record and predict data growth rates without complicated tools.

Naming Tablespaces

Name tablespaces descriptively using a maximum of eight characters. Although Oracle8i tablespace names can be 30 characters long, portable UNIX file names are restricted to 14 characters. The recommended standard for a data file basename is tn.dbf, where t is a descriptive tablespace name and n is a two-digit string. Because the extension plus the two-digit string occupy a total of six characters, only eight characters remain for the tablespace name.

Descriptive names enable the data file to be associated with the tablespace that uses it. For example, the names GLD and GLX might be used for the tablespaces storing General Ledger data and indices, respectively.


Do not embed reminders of the word "tablespace" in your tablespace names. Tablespaces are distinguishable by context, and names do not need to convey information on type. 

Exploiting the OFA Structure for Oracle Files

Table A-7 describes the syntax used for identifying classes of files.

Table A-7 Directory Structure Syntax for Identifying Classes of Files  
Directory Structure Syntax  Description 


User data directories 


User home directories 


User application software directories 


Oracle apps software subtrees 


Oracle Server software subtrees 


Oracle Server 8.1.7 distribution files 


sab database administrative subtrees 


sab database archived log files 


Oracle data directories 


sab database files 


sab database redo log files 

OFA File Mapping

Table A-8 shows a hierarchical file mapping of a sample OFA-compliant database, including each file mount point, application, database, and tablespace. The file names indicate the file type (control, log, or data).

Table A-8 Hierarchical File Mapping for OFA Installation  
Directory  Description 


Root mount point 


User data mount point 1 


Subtree for app software 


Home for oracle software user 


Subtree for database admin files 


Subtree for Support logs 


Admin subtree for db_name1 database 


Admin subtree for db_name2 database 


Online documentation 


Subtree for local Oracle software 


An Oracle6 admin package 


An Oracle7 admin package 


Distribution files 


ORACLE_HOME for 8.0.6 instances 


ORACLE_HOME for 8.1.6 instances 


Home directory for a user 


Home directory for a user 


Subtree for Oracle data 


Subtree for db_name1 database files 


Subtree for db_name2 database files 


User data mount point 2 


Subtree for login home directories 


Home directory for a user 


Home directory for a user 


Subtree for Oracle data 


Subtree for db_name1 database files 


Subtree for db_name2 database files 


User data mount point 3 


Subtree for Oracle data 


Subtree for db_name1 database files 


Subtree for db_name2 database files 

Raw Device Sizes

Choose a small set of standard sizes for all raw devices that can be used to store Oracle database files. In general, standardizing on a single size is recommended. If a single size is used, raw files can be moved from one partition to another safely. The size should be small enough so that a fairly large number can be created but large enough to be convenient.

For example, a 2 GB drive could be divided into 10 partitions of 200 MB each. This is a good balance between size and number. Any tablespace using raw devices should stripe them across several drives. If possible, use a logical volume manager to do the stripping.

File Mapping for Multiple-Instance OFA Database

When using the Oracle Parallel Server, select one node to act as the Oracle administrative home for the cluster. The administrative home contains the administrative subtree. Create subdirectories for each instance accessing the database within the bdump, cdump, logbook, pfile, and udump directories of ~/admin/d/. Mount the admin directory for the administrative home as the admin directory for every instance. An example is shown in Table A-9.

Table A-9 Administrative Directory Structure for Dual-Instance Oracle Parallel Server
Directory  Description 


administrative directory for sab database 


directory for miscellaneous scripts 


log archive dest for all instances 


archived redo log file 


directory for background dump files 


background dump dest for inst1 instance 


background dump dest for inst2 instance 


directory for core dump files 


core dump dest for inst1 instance 


core dump dest for inst2 instance 


directory for creation scripts 


SQL script to create inst database 


directory for exports 


January 20, 2000 full export dump file 


directory for export parfiles 


directory for import parfiles 


directory for inst logbook entries 


directory for inst1 instance reports 


v$parameter report for inst1 instance 


directory for inst2 instance reports 


v$parameter report for inst2 instance 


dba_users report 


directory for instance parameter files 


directory for inst1 instance parameters 


instance parameters for inst1 instance 


directory for inst2 instance parameters 


instance parameters for inst2 instance 


directory for user dump files 


user dump dest for inst1 instance 


user dump dest for inst2 instance 

Directory Structure

The following section describes the directory structure for OFA compliant installations.

Oracle Base Directory

The Oracle base directory is the root of the Oracle directory structure. When installing an OFA-compliant database using the Oracle Universal Installer, the default Oracle base directory is set to /pm/app/oracle. Table A-10 describes an Oracle base directory structure and content.

Table A-10 Oracle Base Directory Structure and Content  
Directory Structure Syntax  Description 


Administrative files 


Online documentation 


Subtree for local Oracle software 


Oracle software 

Oracle Home Directory

If you install an OFA-compliant Oracle Server, the Oracle home directory is /pm/app/oracle/product/release_number. Table A-11 describes the Oracle home directory structure and content. Under UNIX, the Oracle home directory contains the subdirectories described in Table A-11, as well as a subdirectory for each Oracle product installed.

Table A-11 Oracle Home Directory Structure and Content  
Directory  Description 


Configuration Assistants 


Binaries for all products 


interMedia Text options 


initsid.ora, lksid 


Installation related files 


Oracle product libraries 


Java classes 


Spatial options 


Xerox Stemmer (for interMedia Text options) 




NLS runtime loadable data 


Common files for all products 


Data gatherer 


Core libraries 


Data options 


Oracle TRACE 






Server files and libraries required for the database 


SLAX parser 



Contents of Product Subdirectories

Table A-12 describes the subdirectories contained in each product subdirectory:

Table A-12 Contents of Product Subdirectories  
Directory  Description 


Administrative SQL and shell scripts (for example, catalog.sql, catexp.sql, and demo.sql


Special directories for other products 


Resource files 


Runtime terminal files 


Demonstration scripts and datafiles 


README files (for example, readmeunix.doc


Product installation scripts 


Product Java classes 


Product libraries and distributed makefiles 


Trace files and log files (for example, orasrv.log and *.trc files) 


U.S. message files and Multilingual Option (formerly National Language Support) message text and binary files (for example, oraus.msg and oraus.msb

Examples of Product Subdirectories

Table A-13 shows examples of product subdirectories and their contents.

Table A-13 Examples of Product Subdirectories  
Directory  Description 


admin, doc, install, lib, log, mesg 


,admin, demo, doc, install, lib, mesg 

File Naming Conventions in the admin Directory

Table A-14 shows the SQL scripts located in the rdbms/admin directory.

Table A-14 admin Directory, File Naming Conventions  
File  Description 


Creates catalog and data dictionary tables and views. The following files are run automatically during all installation:



The catproc.sql file in turn runs the scripts for creating the standard PL/SQL packages, such as DBMS_SQL and DBMS_OUTPUT. 


Downgrade scripts 


Additional database packages 


Upgrade scripts 


Creates tables and views for database utilities 

Filename Extensions

Table A-15 describes filename extensions.

Table A-15 Filename Extensions  
Extension  Description 


Object file libraries; Ada runtime libraries 


Oracle audit file 


X11 font description file 


X11 bitmap file 


C source file 


SQL*Loader control file; Oracle Server control file 


SQL*Loader datafile 


Oracle Server tablespace file 


Export file 


ASCII text file 


Shell script file for setting environment 


C header file; also, sr.h is a SQL*Report Writer help file 


Java class archive 


UNIX manual page 


Output of SQL*Plus scripts 


Installation log files; Oracle Server redo log files 


make files 


NLS message file (binary) 


NLS message file (text) 


Object module  


Oracle configuration files 


Installation prototype files 


Pro*C source file 


Pro*COBOL source file 


printer driver file 


Bourne shell script file 


SQL* script files  


Bourne shell script file 


SQL* script file 


Trace files 


Bourne shell script file 


Uniform Terminal Definitions 


Zip file 

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