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Startup and shutdown Method

When startup command is issued, Oracle looks for the parameter file in following order.

1. Spfile.ora

2. init.ora

Oracle look for the parameter file in O!"#$%&'O(%)d*s

We can startup the data*ase instance with following options.

1. startup

2. startup nomount

+. Startup mount

startup pfile-)location)filename-

. startup upgrade

/. startup mount restrict

1. startup:-

1. It will read the parameter file.

2. It will start the *ackground processes and allocate memor0 S"3. 4 Instance started.

+. It reads the controlfile. 4Instance mounted.

. 5h0sicall0 checks the datafiles and redolog files.

/. #hecks the S#6 num*er of the datafiles and controlfiles.

It is used in normal situations.

If the S#6s in the control files don-t match some of the S#6s in the data files headers7the

*ackground process smon3 will automaticall0 perform an instance reco8er0 *efore opening the

data*ase.

2. startup mount:--

It will do 1,2 and +.

It will not do and /.

#an *e used when9:: !eco8er0 is needed for the entire data*ase, ;lash*ack is to *e performed,

an0 feature like archi8e log is to *e ena*led or disa*led.

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3. startup nomount:--

It will do 1 and 2.

It will not do +, and /.

#an *e used when9:: #reating data*ase and creating controlfile.

4. startup upgrade:--

It will do 1 to / and

. i8e the option of upgrading data*ase.

=. sers cannot connect to the data*ase.

#an *e used to upgrade the data*ase dictionar0

Data*ase must *e shutdown and restarted for users to connect.

5. startup mount restrict:--

It will read 1, 2 and +.

It will not read and /.

sed when the data*ase is dropped.

Changing the status:--

Alter database mount

?his command can *e used when data*ase is in nomount state, this will read the controlfiles

and mount the data*ase.

Alter database open

?his command can *e used when data*ase is mounted.

?his will read the datafiles and redolog file and will check if the datafiles are consistent. "llows

the users to connect to the data*ase,

Alter database close

?his command can *e used when data*ase open. ?his will release the datafiles and redolog

files.

ser connections will not *e allowed. Status will change to mount.

Alter database dismount

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?his command can *e used when data*ase is at mount state. ?his will release the control file

and change the status to nomount.

!he database can be shutdown with the "ollowing options:--

Shutdown:--

6o new user connections can *e made to the data*ase once the command is issued. Oracle

waits for all users to e@it their sessions *efore shutting down the data*ase. 6o instance

reco8er0 is needed when 0ou restart data*ase, it will *e consistent when it-s shut down in this

wa0. Oracle closes the data files and terminates the *ackground processes. Oracle-s S" is

deallocated.

Shutdown transactional:--

6o new user connections are permitted once the command is issued. %@isting users can-t start

a new transaction and will *e disconnected. If a user has a transaction in progress, oracle will

wait until the transaction is completed *efore disconnecting the user. "fter all e@istingtransactions are completed. Oracle shuts down the instance and deallocates memor0. Oracle

writes all redo log *uffers and data *lock *uffers to disk. 6o instance reco8er0 is needed

*ecause the data*ase is consistent.

A%I6 DA(S&$O#B.sleepseconds > C.C13%6D)

Shutdown immediate:--

6o new user connections are allowed once the command is issued. Oracle immediatel0

disconnects all users. Oracle terminates all currentl0 e@ecuting transactions. ;or all transactions

terminated midwa0, oracle will perform a roll*ack so that data*ase ends up consistent.

Sometimes oracle ma0 *e *us0 rolling *ack the transactions it Eust terminated. Oracle

terminates the *ackground processes and deallocates memor0. 6o instance reco8er0 is needed

upon starting up the data*ase *ecause it is consistent when shut down.

Shutdown abort:--

6o new connections are permitted once the command is issued. %@isting sessions are

terminated, regardless of whether the0 ha8e an acti8e transaction or not. Oracle doesn-t roll

*ack the terminated transactions. Oracle doesn-t write the redo log *uffers and data *uffers todisk. Oracle terminates the *ackground processes, deallocates memor0 immediatel0, and

shutdown. pon restarting, oracle will perform an automatic instance reco8er0, *ecause the

data*ase isn-t guaranteed to *e consistent when shut down.