The Oracle server provides a number of standard views to obtain information on the database and

instance. These views include:

V$SGA: Queries the size of the size of the instance for the shared pool, log buffer, data buffer

cache, and fixed memory sizes(operating system-dependent).

V$INSTANCE: Queries the status of the instance, such as the instance mode, instance name, startup time, and host name.

V$PROCESS: Queries the background and server processes created for the instance.

V$BGPROCESS: Queries the background processes created for the instance.

V$DATABASE: Lists status and recovery information about the database name, the unique database identifier, the creation data, the control file creation date and time, the last database checkpoint, and other information.

V$DATAFILE: Lists the location and names of the data files that are contained in the database. It includes information relating to the number and name, creation date, status(online or offline), enable(read-only, read-write), last data file checkpoint, size, and other information.