I get the ORA-600 error while I'm trying to create a database. After I execute the database creation script, it gives me the message "Disconnection forced." When I connect to the database, it works fine till the mount stage, but when I give the command "alter database open" it hangs. What could be the cause of this?
ORA-00600 errors are untrapped errors. Basically this means that Oracle knows there is a problem, but does not know which error message to give you, so it raises ORA-00600 instead. This error is accompanied by some parameters in brackets. The first bracket parameter is the location in the Oracle code that is causing the error to be thrown. For instance, you might see an error similar to the following:
ORA-600    
The first bracket is the key to solving this problem. Metalink has an ORA-660 Argument Lookup tool (see Note 153788.1 for more information) to help you diagnose these errors. If the lookup tool does not help you solve the problem, then the best course of action is to file a TAR with Oracle Support.
If you do not have an Oracle Support contract, then your only other option is to do a Google search on the same error with the same first argument in the brackets to see if someone on the Internet has posted a resolution for this problem.