I want to monitor my oracle db and need to get the info related to number of connections, thread count etc. pls let me know the system tables from which I can query these info. i.e am interested in below information obtained from mysql when "show status" command is executed.
Rather than trying to monitor it as if it was mysql why dont you get a tool like Enterprise manager. It does take time to setup but it will show you a lot, not just about the database but also server stats etc.