Hi,

It's get connected to SID only,
The SID is a site/system identifier. SID plus the Oracle_home are hashed together in Unix to create a unique key name for attaching an SGA. If your Oracle_sid is not set
correctly, you'll get "oracle not available" since it cannot
attach to a shared memory segment that is identified by magic key. On NT, we don't use shared memory but the SID is still important. We can have more then 1 database on the same oracle home so we need a way to id them.


Vicky