I have installed Oracle 9.0 on Windows 2000 server. I created a database, and it allowed me to log in to SQL*Plus before restarting. Once I restarted, the services shows that the database has started, but SQL*Plus is not allowing me to log in. It gives the following errors:
ORA-1034 - Oracle not available ORA-27101 - shared memory realm does not exist
I tried a lot of ways to fix this, but I was not successful. I have checked my Listener.Ora and Tnsnames.Ora files, and set the Environment variables, ORACLE_HOME and ORACLE_SID, and everything looks fine. Please help me in figuring this out.
The next place to look is in your Alert Log. It is possible for the services to be running but for the database to be down. The reverse is not true. The services need to be running if the database is running.
It looks like the service started, which attempts to start the database. The database is not started otherwise you would not have received the ORA-1034 error.
Your Alert Log will contain detailed information about why the database could not be started. You should see the database attempt to start, followed by some error messages. There are many reasons why the database did not start, so you'll have to narrow it down some more from information in the Alert Log. The Alert Log is in the directory specified by your BACKGROUND_DUMP_DEST parameter.