Oracle Windows registry tips Oracle Database Tips by Donald Burleson Updated June 3, 2015

 

Question:  I have multiple ORACLE_HOME directories on my Windows server and I need to understand the registry entries for these settings.

 

Answer: In Windows, there is a place called the Registry (like the SYSGEN Parameter file on VMS) that stores values that are used by the OS and various software packages, and that includes Oracle. 

 

The command at the Windows 'run' prompt is 'regedit'. I won't get into Registry Editing here, since that is a full topic in itself, but below are some of the main entries, and what they are for.
 

HKEY_LOCAL_MACHINE\Software\Oracle   -  is the home registry key.

ORA_sid_PFILE - the path to your pfile

ORA_sid_AUTOSTART - tells whether the sid should start when the service does.  Generally this should be TRUE

ORA_sid_SHUTDOWN - tells whether to shutdown when the service stops.  Again, this should be TRUE.

ORA_sid_SHUTDOWN_TYPE - How to shutdown by default when the service stops. IMMEDIATE works here.

ORACLE_HOME - path to Oracle Home

NLS_LANG - nls language setting for the server

 

The Windows registry allows for multiple instances and your can adjust the following registry entries for each Oracle instance:

 

HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\ALL_HOMES\IDx

HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_ora10g_Home1
HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_ora10g_Home2

For complete details, see notes 124353.1 and note 208256.1 from MOSC.

Main Oracle Windows Registry keys

To make Oracle on Windows automatically start and stops we use these registry parameters:

hkey_local_machine->software->oracle->key_home_name->ora_sid_autostart
and
hkey_local_machine->software->oracle->key_home_name->ora_sid_shutdown

Also, the registry hkey_local_machine->software->oracle->key_home_name holds some other very useful entries:

• oracle_base: The location of the oracle base directory for this oracle home.
• oracle_home:  The location of the oracle home directory for this oracle home.
• oracle_sid:  The oracle system identifier or sid.
• sqlpath:  The location of sql scripts.
• rdbms_control:  The location of Oracle control files and the spfile/pfile for this instance.

To check the Oracle Windows Registry

Open the registry with regedit.  Always back up the registry before making changes. Navigate to the key entry in the Windows registry:

HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\oracle_home_name.

There will be a key called:

ORA_SID_AUTOSTART. 

SID is your database System ID and SID should be set to TRUE. 

If not the server starts but does not start the database.  There is also an ORA_SID_SHUTDOWN which you want to be TRUE so that if the server is shut down the service will shutdown the database.

If you want to manually start the database set ORA_SID_AUTOSTART to FALSE.  The Windows service will start but not the Oracle database. 

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The difference between ORACLE_HOME and ORACLE_BASE

 

Check oracle_home Tips

 

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