Suspending and Resuming a Oracle Database

Suspend means freezing the I/O process of writing to datafile and control-files.
When we put database in suspended state all I/O operation are going to completed and new request in queued state means wait until database is in resumed again.

Use
Suspend/Resume is useful in mirror a disk or file and then split the mirror,backup and restore solution. It is not used commonly in daily activities.

Check the status of Database is suspend or resume

-- Supspended state
SQL> SELECT DATABASE_STATUS FROM V$INSTANCE;
DATABASE_STATUS
---------
SUSPENDED

--Resume state
SQL> SELECT DATABASE_STATUS FROM V$INSTANCE;
DATABASE_STATUS
---------
ACTIVE


Suspend database

ALTER SYSTEM SUSPEND;


Resume database

ALTER SYSTEM RESUME;