Re: Why DB_Name 4 chars only.

For most unix Platforms, the SID can be upto 8 characters in length. For NT, I think, it should be 4 mainly because of DOS file name limitations. I dont have the resources on hand, but I guess one could confirm this by just trying to mount an instance with varying SID Names, until you get the error : ORA-27034 skgfrcre: maximum length of ORACLE_SID exceeded

Also, this is from a Steve Adams post on this subject, that I found on comp.databases.oracle :

Internally, Oracle allows 9 bytes for the database name and 16 bytes for the instance name. These are null terminated strings, so the available length is one less. For the instance name, all characters, even beyond 15 are significant for distinguishing instances, but if an instance name exceeds 15 characters Oracle gives up and does not record its name internally at all. This is fine in a single instance configuration, but I would not be confident to try it in an OPS environment, although logic says that it should be OK.

Regards
Raj

                                                                                                                     
                    "Igor Neyman"                                                                                    
                    <ineyman_at_perce        To:     Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>        
                    ptron.com>            cc:                                                                        
                    Sent by:              Subject:     Re: Why DB_Name 4 chars only.                                 
                    root_at_fatcity.c                                                                                   
                    om                                                                                               
                                                                                                                     
                                                                                                                     
                    July 30, 2002                                                                                    
                    04:31 PM                                                                                         
                    Please respond                                                                                   
                    to ORACLE-L                                                                                      
                                                                                                                     
                                                                                                                     

Database name is limited to 9 characters, see "name" column in v$database. Instance name is limited to 181 characters (at least according to inst_name in v$active_instances).

All this under 8.1.5.

Igor Neyman, OCP DBA
ineyman_at_perceptron.com

• Original Message ----- To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> Sent: Tuesday, July 30, 2002 4:08 PM

> Hi,
> What is the reason behind DB_Name/SID usually 4 chars
> length only. I have a customer who is asking us to
> create instance/db with 6 chars length. We usually
> keep instance name and db_name parameters same in .ora
> file. Can someone please explain the reason behind
> db_name 4 chars only. Is it a common practice to keep
> SID/db_name/instance name parameters same (for example
> PBDS).
>
> thanks
> Srinivas

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: 
  INET: Rajesh.Rao_at_jpmchase.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).