The options I selected are a) Oracle 9i Database 9.0, b) Enterprise Edition and c) General purpose.
I tried to log in using system/manager but I couldn't. Is the reason that the DB Assistant fails or because I didn't enter the host (I didn't know what to enter in this field)?
If, in fact, you do have a database created, and it is open and available but you still get these errors trying to log in through SQL*Plus, here are a few more things to check. It could be that your ORACLE_SID and ORACLE_HOME are not set correctly. The problem may also stem from not having the appropriate privileges at the OS level. You must connect to the server with an appropriately privileged account. If you do not have operating system authentication, you will need to provide a username and password that has SYSDBA privileges.
One more thing to watch for is that the SID name you have chosen for your database does not contain a non-alphanumeric character such as an underscore or a dash. The SID can only contain alphanumeric characters.
This was first published in November 2005