Top-level names of the Optimal Flexible Architecture directory tree differ between Windows and UNIX.

However, main subdirectory names and file names are the same on both operating systems.

On Windows, Oracle base is associated with an Oracle home directory. ORACLE_BASE is defined in the registry (for example, in HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_HOMENAME).

On UNIX, ORACLE_BASE is associated with a UNIX user's environment.

The goal of Optimal Flexible Architecture is to place all Oracle software under one ORACLE_BASE directory and to spread files across different physical drives as your databases increase in size.

On UNIX, although everything seems to be in one directory on the same hard drive, files can be on different hard drives if they are symbolically linked or have that directory as a mount point.

On Windows, you can use volume mount points to mount files on different hard drives to a single directory. You can have oradata directories on multiple drives, with data files in each one, on Windows version which does not support volume mount points.

Oracle recommends that you use one logical drive to store your database administration files and that you place other files, as needed, on other logical drives in an oradata\DB_UNIQUE_NAME directory.

In the following example, there are four logical drives for a database named prod:

• c:\ contains an Oracle home and database administration files.

• f:\ contains redo log files. The F:\ drive could also represent two physical drives that have been striped to increase performance.

• g:\ contains one of the control files and all tablespace files. The G:\ drive can also use a RAID Level-5 configuration to increase reliability.

• h:\ contains the second control file.

The directory structure looks similar to this:

c:\app\username\product\11.2.0   --First logical drive
    \dbhome_1                  --Oracle home
      \bin                 --Subtree for Oracle binaries
      \network             --Subtree for Oracle Net
      \...
    \admin                 --Subtree for database administration files
      \prod                --Subtree for prod database administration files
        \adump             --Audit files
        \dpdump		            --Default directory for data pump operations.
        \pfile             --Initialization response file

f:\app\username\product\11.2.0   --Second logical drive (two physical drives, striped)
    \oradata               --Subtree for Oracle Database files
      \prod                --Subtree for prod database files
        redo01.log         --Redo log file group one, member one
        redo02.log         --Redo log file group two, member one
        redo03.log         --Redo log file group three, member one

g:\app\username\product\11.2.0   --Third logical drive (RAID level 5 configuration)
    \oradata               --Subtree for Oracle Database files
      \prod                --Subtree for prod database files
        CONTROL01.CTL      --Control file 1
        EXAMPLE01.DBF      --EXAMPLE tablespace data files
        SYSAUX01.DBF       --SYSAUX tablespace data files
        SYSTEM01.DBF       --System tablespace data file
        TEMP01.DBF         --Temporary tablespace data file
        USERS01.DBF        --Users tablespace data file

h:\app\username\product\11.2.0   --Fourth logical drive
    \oradata               --Subtree for Oracle Database files
      \prod                --Subtree for prod database files
        CONTROL02.CTL      --Control file 2