At this
point, none of the physical files in the database have been opened, and the
instance is in the NOMOUNT state. (Note that the number of parameters that
must be defined in the SPFILE in Oracle Database 10g and Oracle Database 11g
as part of the initial installation setup have been greatly reduced. We described
the initialization parameters required in Oracle Database 11g in Chapter 2.)
There are problems that can prevent an instance from starting. For example,
there may be errors in the initialization file, or the operating system may not be
able to allocate the requested amount of shared memory for the SGA. You also
need the special privilege SYSOPER or SYSDBA, granted through either the
operating system or a password file, to start an instance.
2. Mounting the database. The instance opens the database??™s control files. The initialization
parameter CONTROL_FILES tells the instance where to find these
control files. At this point, only the control files are open. This is called the
MOUNT state, and the database is accessible only to the database administrator.
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