Let’s remember the ORACLE database startup options.

NOMOUNT : If we choose “nomount” option to start our ORACLE database , system first read “init.ora” file to get database configuration and related parameters thus database can start background processes.

MOUNT : If we upgrade our database startup option to “mount” , then database reads “Controlfile” entries to get information about physical database locations and after that database is getting ready for open status.

OPEN : After that step our Oracle database status is now “open” and we can reach all database informations over the system.It also shows us our database integrity is OK.

Also we can check our database status via sql plus like below ;

SQL> select status from v$instance;

for example ;

SQL>select instance_name,status from v$instance;

INSTANCE_NAME    STATUS
—————-               ————
ORCLDB1                     OPEN
ORCLDB2                    OPEN
ORCLDB3                    OPEN