Always stop the database server explicitly before closing the operating system session.
If you close an operating system session where a database server is running, or if you use an operating system command to stop the database server (other than the UNIX command shown in the previous section), the server shuts down, but not cleanly. Next time the database is loaded, recovery happens automatically. For information on system recovery, see Chapter 13, “System Recovery and Database Repair.”
An example of a command that does not stop a server cleanly is stopping the process in the Windows Task Manager Processes window.
