There are various stages that the database undergoes before a database is opened for use. In this article, you will learn about the oracle database startup and shutdown procedure.
Table of Content - Oracle Database Startup and Shutdown Procedure |
This is the state when the control file, online redo log files, and the database files are closed and are not accessible. The Oracle instance is available. Some of the v$ views (dynamic performance views) are available during this state.
A database may be brought to this state to perform operations.
1. Creating a database.
2. Recreating the control file.
Ex: V$session, v$instance, v$database etc.
If you want to enrich your career and become a professional in Oracle DBA, then enroll in "Oracle DBA Online Training" - This course will help you to achieve excellence in this domain. |
This is the next phase through which the database passes. During this stage, the control file is opened and the existence of all the database files and online redo log files is verified.
A database may be brought to this state to perform operations like
The database is opened. During this stage, the data files and the online redo log files are opened and ready to use. Oracle doesn’t allow you to open the database if any of the datafile or online redo log file is missing or corrupted.
A database may be opened in read-only mode as well as in reading-write mode. The status may be found by querying the v$database dynamic performance view. The query for this is as below
Sql>select open_mode from v$database:
In the read-only mode, the database may be queried but one cannot perform the dml operations.
Note: To startup or shutdown the database, you need to logon as “sys as sysdba” or with any user account having sysdba role assigned.
There are other options available like one can start the database in a restricted mode. This is used during maintenance activities, upgrades, etc. Only those users having restricted session privilege can logon into the database.
Are you planning to build a career in Oracle DBA? Sign up for this Oracle DBA Certification Training in Hyderabad to begin your journey today!
Oracle has three shutdown modes namely normal, immediate, and abort.
This is the default mode of shutting down the database. During this state, the oracle server waits for all the users to disconnect.
Waits until all the transactions are completed and then shuts down the database. During this state, no new connections are permitted.
This option will disconnect all the sessions; roll back all the running transactions and shut down the database. During the next startup, no instance recovery is needed.
This option doesn’t roll back any transactions and simply brings down the database. In layman’s terms, it is just like pulling the power plug of the television. Any subsequent database startup needs an instance recovery to be initiated by smon.
Any backup taken after shutting down the database in abort mode will not be consistent. It is recommended to use the first three methods to shut down the database for a consistent backup.
Related Article: A Complete Guide for Oracle DBA Tutorial |
From the information available, it might appear that using an abort option isn’t a good idea. But however, in the case of large databases, it may take a while and hence the option of abort can be judiciously utilized as below
1. Shu abort
2. startup restrict
3. Shu immediate
4. Startup mount restrict
This will be a clean shutdown and will be much quicker than the conventional methods. However, experienced dba always prefers to wait rather than use the previous options.
Related Articles:
Oracle DBA Interview Questions and Answers
Our work-support plans provide precise options as per your project tasks. Whether you are a newbie or an experienced professional seeking assistance in completing project tasks, we are here with the following plans to meet your custom needs:
Name | Dates | |
---|---|---|
Oracle DBA Training | Dec 07 to Dec 22 | View Details |
Oracle DBA Training | Dec 10 to Dec 25 | View Details |
Oracle DBA Training | Dec 14 to Dec 29 | View Details |
Oracle DBA Training | Dec 17 to Jan 01 | View Details |
Ravindra Savaram is a Technical Lead at Mindmajix.com. His passion lies in writing articles on the most popular IT platforms including Machine learning, DevOps, Data Science, Artificial Intelligence, RPA, Deep Learning, and so on. You can stay up to date on all these technologies by following him on LinkedIn and Twitter.