Oracle8i Administrator's Reference
Release 3 (8.1.7) 64 Bit for SGI IRIX

Part Number A87435_01
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A
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.

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 

q 

A string denoting that Oracle data is stored here 

dm 

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 

pm 

A mount point name 

h 

A standard directory name 

u 

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 

pm 

A mount point name 

h 

A standard directory name 

v 

The version of the software 

For example, /u01/app/oracle/product/817 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 

adhoc 

Ad hoc SQL scripts for a particular database 

arch 

Archived redo log files 

adump 

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

bdump 

Background process trace files 

cdump 

Core dump files 

create 

Programs used to create the database 

exp 

Database export files 

logbook 

Files recording the status and history of the database 

pfile 

Instance parameter files 

udump 

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 

pm  

A mount point name described previously in this chapter 

q 

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

d 

The DB_NAME of the database 

t 

An Oracle tablespace name 

n 

A two-digit string 


Note:

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 

SYSTEM 

Data dictionary segments 

TEMP 

Temporary segments 

RBS 

Rollback segments 

USERS 

Miscellaneous user segments 

INDX 

Index associated with data in USERS tablespace 

OEM_REPOSITORY 

repository for Oracle Enterprise Manager 

DRSYS 

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.


Note:

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 

/u[0-9][0-9] 

User data directories 

/*/home/* 

User home directories 

/*/app/* 

User application software directories 

/*/app/applmgr 

Oracle apps software subtrees 

/*/app/oracle/product 

Oracle Server software subtrees 

/*/app/oracle/product/8.1.7 

Oracle Server 8.1.7 distribution files 

/*/app/oracle/admin/sab 

sab database administrative subtrees 

/*/app/oracle/admin/sab/arch/* 

sab database archived log files 

/*/oradata 

Oracle data directories 

/*/oradata/sab/* 

sab database files 

/*/oradata/sab/*.log 

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 

/u01/ 

User data mount point 1 

/u01/app/ 

Subtree for app software 

/u01/app/oracle/ 

Home for oracle software user 

/u01/app/oracle/admin/ 

Subtree for database admin files 

/u01/app/oracle/admin/TAR/ 

Subtree for Support logs 

/u01/app/oracle/admin/db_name1/ 

Admin subtree for db_name1 database 

/u01/app/oracle/admin/db_name2/ 

Admin subtree for db_name2 database 

/u01/app/oracle/doc/ 

Online documentation 

/u01/app/oracle/local/ 

Subtree for local Oracle software 

/u01/app/oracle/local/aps6/ 

An Oracle6 admin package 

/u01/app/oracle/local/aps7/ 

An Oracle7 admin package 

/u01/app/oracle/product/ 

Distribution files 

/u01/app/oracle/product/8.0.6/ 

ORACLE_HOME for 8.0.6 instances 

/u01/app/oracle/product/8.1.6/ 

ORACLE_HOME for 8.1.6 instances 

/u01/app/ltb/ 

Home directory for a user 

/u01/app/sbm/ 

Home directory for a user 

/u01/oradata/ 

Subtree for Oracle data 

/u01/oradata/db_name1/ 

Subtree for db_name1 database files 

/u01/oradata/db_name2/ 

Subtree for db_name2 database files 

/u02/ 

User data mount point 2 

/u02/home/ 

Subtree for login home directories 

/u02/home/cvm/ 

Home directory for a user 

/u02/home/vrm/ 

Home directory for a user 

/u02/oradata/ 

Subtree for Oracle data 

/u02/oradata/db_name1/ 

Subtree for db_name1 database files 

/u02/oradata/db_name2/ 

Subtree for db_name2 database files 

/u03/ 

User data mount point 3 

/u03/oradata/ 

Subtree for Oracle data 

/u03/oradata/db_name1/ 

Subtree for db_name1 database files 

/u03/oradata/db_name2/ 

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.

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-9 describes an Oracle base directory structure and content.

Table A-9 Oracle Base Directory Structure and Content  
Directory Structure Syntax  Description 

admin 

Administrative files 

doc 

Online documentation 

local 

Subtree for local Oracle software 

product 

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-10 describes the Oracle home directory structure and content. Under UNIX, the Oracle home directory contains the subdirectories described in Table A-10, as well as a subdirectory for each Oracle product installed.

Table A-10 Oracle Home Directory Structure and Content  
Directory  Description 

assistants 

Configuration Assistants 

bin 

Binaries for all products 

ctx 

interMedia Text options 

dbs 

initsid.ora, lksid 

install 

Installation related files 

lib 

Oracle product libraries 

jlib 

Java classes 

md 

Spatial options 

mlx 

Xerox Stemmer (for interMedia Text options) 

network 

Net8 

nlsrtl 

NLS runtime loadable data 

ocommon 

Common files for all products 

odg 

Data gatherer 

oracore 

Core libraries 

ord 

Data options 

otrace 

Oracle TRACE 

plsql 

PL/SQL 

precomp 

Precompilers 

rdbms 

Server files and libraries required for the database 

slax 

SLAX parser 

sqlplus 

SQL*Plus 

Contents of Product Subdirectories

Table A-11 describes the subdirectories contained in each product subdirectory:

Table A-11 Contents of Product Subdirectories  
Directory  Description 

admin 

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

admin/* 

Special directories for other products 

admin/resource 

Resource files 

admin/terminal 

Runtime terminal files 

demo 

Demonstration scripts and datafiles 

doc 

README files (for example, readmeunix.doc

install 

Product installation scripts 

jlib 

Product Java classes 

lib 

Product libraries and distributed makefiles 

log 

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

mesg 

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-12 shows examples of product subdirectories and their contents.

Table A-12 Examples of Product Subdirectories  
Directory  Description 

rdbms 

admin, doc, install, lib, log, mesg 

sqlplus 

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

File Naming Conventions in the admin Directory

Table A-13 shows the SQL scripts located in the rdbms/admin directory.

Table A-13 admin Directory, File Naming Conventions  
File  Description 

cat*.sql 

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

catproc.sql

catrep.sql

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

d*.sql 

Downgrade scripts 

dbms*.sql 

Additional database packages 

u*.sql 

Upgrade scripts 

utl*.sql 

Creates tables and views for database utilities 

Filename Extensions

Table A-14 describes filename extensions.

Table A-14 Filename Extensions  
Extension  Description 

.a 

Object file libraries; Ada runtime libraries 

.aud 

Oracle audit file 

.bdf 

X11 font description file 

.bmp 

X11 bitmap file 

.c 

C source file 

.ctl 

SQL*Loader control file; Oracle Server control file 

.dat 

SQL*Loader datafile 

.dbf 

Oracle Server tablespace file 

.dmp 

Export file 

.doc 

ASCII text file 

.env 

Shell script file for setting environment 

.h 

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

.jar 

Java class archive 

.l 

UNIX manual page 

.lis 

Output of SQL*Plus scripts 

.log 

Installation log files; Oracle Server redo log files 

.mk 

make files 

.msb 

NLS message file (binary) 

.msg 

NLS message file (text) 

.o 

Object module  

.ora 

Oracle configuration files 

.orc 

Installation prototype files 

.pc 

Pro*C source file 

.pco 

Pro*COBOL source file 

.ppd 

printer driver file 

.sh 

Bourne shell script file 

.sql 

SQL* script files  

.sys 

Bourne shell script file 

.tab 

SQL* script file 

.trc 

Trace files 

.tut 

Bourne shell script file 

.utd 

Uniform Terminal Definitions 

.zip 

Zip file 


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