Re: BUG ALERT!!!! on SID names

From: oracle <oracle_at_nightmare.com>
Date: 1997/03/01
Message-ID: <3317CE50.33D6@nightmare.com>#1/1

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Strategic Data Systems wrote:

>
> In article <5f51d1$pc6$2_at_news.inc.net>, sds_at_dataplusnet.com says...
> >
> >Running Oracle 7.1.6 on AIX 4.1.4 and tried to create another

instance.
> >Couldn't create because after a connect internal(ORACLE_SID=smtest) in sqldba, I was

> >connected to an existing instance(nwtest).
> >
> >Went around with Oracle Support for 4 days and they finally said:
> >
> >'Oracle hashes the SID name to a number and uses the number to make

the connection.

> >Apparently 'smtest' and 'nwtest' hash to the same number!!!!.
> >
> >The fix is to change the sid name to something other than smtest.
> >
>
> Oracle got back again and said this is fixed in 7.2 and up.

It really is not a bug. They just did not use a very good hashing algorithm pre 7.2. It uses the ORACLE_HOME and sid to hash to the memory location. 7.2 and newer can still has to the same address but it is not as likely.

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<DT>Strategic Data Systems wrote: 
>  
> In article <5f51d1$pc6$2_at_news.inc.net>, sds_at_dataplusnet.com
says... 
> > 
> >Running Oracle 7.1.6 on AIX 4.1.4 and tried to create another
instance. 
> >Couldn't create because after a connect internal(ORACLE_SID=smtest)
in sqldba, I was 
> >connected to an existing instance(nwtest). 
> > 
> >Went around with Oracle Support for 4 days and they finally said: 
> > 
> >'Oracle hashes the SID name to a number and uses the number to
make the connection. 
> >Apparently 'smtest' and 'nwtest' hash to the same number!!!!. 
> > 
> >The fix is to change the sid name to something other than smtest. 
> > 
>  
> Oracle got back again and said this is fixed in 7.2 and up. 
 </DT>

<DT>It really is not a bug.  They just did not use a very good hashing algorithm pre 7.2.  It uses the ORACLE_HOME and sid to hash to the memory location.   7.2 and newer can still has to the same address but it is not as likely.</DT>

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------------2F37521454083-- Received on Sat Mar 01 1997 - 00:00:00 CST