1.Oracle Basic commands

To start the database in NOMOUNT state

SQL>STARTUP NOMOUNT;

To start the database in MOUNT state

SQL>STARTUP MOUNT;

To start the database in OPEN state

SQL>STARTUP OPEN;

To MOUNT the database that’s in NOMOUNT state

SQL> ALTER DATABASE MOUNT;

To OPEN the database that’s in MOUNT state

SQL> ALTER DATABASE OPEN;

To verify the open state of the database ( if the database is in NOMOUNT or MOUNT or OPEN state)

SQL> SELECT STATUS FROM V$INSTANCE;

To start the database in restricted mode (database is currently shutdown)

SQL>STARTUP RESTRICT;

To enable restricted mode on an already running database

SQL>ALTER SYSTEM ENABLE RESTRICTED SESSION;

To disable the restricted session on an already running database

SQL>ALTER SYSTEM DISABLE RESTRICTED SESSION;

To verify RESTRICTED mode

SQL> SELECT LOGINS FROM V$INSTANCE;

LOGINS RESTRICTED

To start the database in read only mode SQL> STARTUP OPEN READ ONLY; or SQL> STARTUP MOUNT;
SQL> ALTER DATABASE OPEN READ ONLY;

To make the database read write

Once a database is started in READ ONLY mode, you have to SHUTDOWN and STARTUP the database to make it READ WRITE

SQL> SHUTDOWN IMMEDIATE;

SQL> STARTUP OPEN;

To verify open mode of the database (READ ONLY or READ WRITE)

SQL> SELECT OPEN_MODE FROM V$DATABASE; OPEN_MODE ——————– READ ONLY

To shut down the database in normal mode

SQL>SHUTDOWN NORMAL;

 To shut down the database in transactional mode

SQL>SHUTDOWN TRANSACTIONAL;

To shut down the database in immediate mode

SQL>SHUTDOWN IMMEDIATE;

 To ABORT the instance

SQL>SHUTDOWN ABORT;

 To force the instance to start (if the normal startup has some problem)

SQL> STARTUP FORCE;

To Quiesce a database

SQL> ALTER SYSETM QUIESCE RESTRICTED; To unquiesce a quiesced database SQL> ALTER SYSTEM UNQUIESCE;

 To verify the quiesced state of the database

SQL> SELECT ACTIVE_STATE FROM V$INSTANCE;

 To suspend database

SQL> ALTER SYSTEM SUSPEND;

 To resume database

SQL> ALTER SYSTEM RESUME;

 To see suspended state of database

SQL> SELECT DATABASE_STATUS FROM V$INSTANCE;