in v$instance what does DATABASE_STATUS colomn mean ? What are its values and their meanings ? I looked at
and it says : DATABASE_STATUS VARCHAR2(17) Status of the database ; which is not clear for me.
The DATABASE_STATUS column, as demonstrated by Legatti, shows if the database is in a suspended state or active state.
The ALTER SYSTEM SUSPEND statement halts all input and output (I/O) to datafiles (file header and file data) and control files. The suspended state lets you back up a database without I/O interference. When the database is suspended all preexisting I/O operations are allowed to complete and any new database accesses are placed in a queued state.