Different statuses of Oracle Database startup

Oracle Database startup involves three steps:

Nomount: Find the initialization file pfile or spfile, create the SGA and start the background process, but do not allow access to the database.

Mount: locate the Control File based on the initialization File, and load the database for some DBA activities, but the user is not allowed to access the database.

Open: Find the Data File according to the control File and Redo the log File so that you can access the database.

 

Shut down four different commands of the database

Shutdown normal (equal to shutdown)

Normally, the database is shut down by default. Normally, the database is shut down in the following circumstances.

• New connections are not allowed

• Wait until the session ends

• Wait until the transaction ends

• Make a checkpoint and close the data file

• The instance is not required to be restored at the next startup.

Shutdown transactional

Transaction processing is disabled to prevent customers from losing work transaction processing the database is closed in the following circumstances

• New connections are not allowed

• Do not wait until the session ends

• Wait until the transaction ends

• Make a checkpoint and close the data file

• The instance is not required to be restored at the next startup.

Shutdown immediate

Immediately shut down the database in the following circumstances

• New connections are not allowed

• Do not wait until the session ends

• Do not wait until the transaction ends

• Rollback)

• Make a checkpoint and close the data file

• No routine recovery is required for the next Startup

Shutdown abort

If the normal and immediate shutdown options do not work, you can abort the current data warehouse routine.

• New connections are not allowed

• Do not wait until the session ends

• Do not wait until the transaction ends

• No checkpoint and no data file is closed

• The instance is required to be restored at the next startup.

 

 

Start database commands

Startup (started to open by default)

Startup nomount

Startup mount

Alter database mount;

Alter database open;

 

Initialize File

Pfile: a text file that can be edited manually.

Spfile: binary file. You cannot manually modify the parameters in the binary file. You can only use database commands to modify the parameters. By default, spfile is used for database startup.

 

View the initialization file path

Show parameter spfile;

 

Create a pfile Based on spfile

Create pfile from spfile;

Create pfile = '/u01/app/pfile. ora' fromspfile;

Create spfile from pfile = '/u01/app/pfile. ora ';

 

View the control file path

Select name from v $ controlfile;

 

View the control file content and rebuild the control file according to ctl. trc.

Alter database backup controlfile to trace as '/u01/app/ctl. trc ';

 

View the location of the data file

Select name from v $ datafile;

 

View the location of the redo log file

Select member from v $ logfile;

 

Database Password File

Windows, $ ORACLE_HOME/database/PWDorcl. ora

Linux/Unix, $ ORACLE_HOME/dbs/orapworcl

The role of the password file is to allow the database's sysdba and sysoper users to log on remotely using the password.

 

Check whether the database allows users to log on to the database remotely

Show parameter remote_login_passwordfile;

If remote_login_passwordfile is EXCLUSIVE, remote connection to the database is allowed.

If remote_login_passwordfile is set to NONE, remote database connection is not allowed.

 

Prohibit users from logging on to the database remotely (restart the database to take effect)

Alter system set remote_login_passwordfile = none scope = spfile;

 

Tablespace

Select * from dba_tablespaces;

 

Data Files

Select * from dba_data_files;

 

Redo log files

Select * from v $ logfile;

 

Redo Log File status

STALE indicates that the data has been submitted to the database, and the blank state indicates that the file is being used.