Oracle Startup procedures

Oracle Startup procedures

It is the Last one stopped and first to start in the landscape.

When Oracle is started in the open mod then only the database is available for users.

The Following Commands are used to start the database in various modes

Startup nomount

Startup mount

Startup Open

Startup restricted (Only during migration or patch application)

Use sqlplus “/as sysdba” in command window

Select status from v$instance;

1.Startup nomount:This phase is used to create control files and database.SGA is created and no data files are mounted and hence It is not used by users. Only selected queries are  allowed.

2.Startup mount: We can start  a DB and mount a database without opening it,allows us to perform specific maintenance operations like

a.change the archive log mode status

3.Startup open:When DB is started using strdbs.cmd it reads the init parameters in the following sequence

1.SPFILE<SID>.ORA

2.SPFILE.ORA

3.INIT<SID>.ORA

4.INIT.ORA

And starts the database in open mode which is available to all the users.