With well over a decade of Oracle experience from version 6 to 11g, I have had my share of interviewing prospective DBA employees in a range from Junior to Senior DBAs. Needless to say in this field, technical competence is the key to any new hire and early on I made the blunder of not asking the write questions during the interview. I am sure every senior person or manager has made this mistake and had to deal with either training the person from scratch or letting them go. Either of these options is not desirable in our fast past business would. So, I decided to write a couple of articles which cover what I believe a Junior, Mid, and Senior Oracle DBA should know to fill their prospective positions.

In this article we will cover what a Junior DBA should know to be successful. If you have any comments or questions, please email me at larry.catt@relidb.com.

Questions:

1. Give the three modes of starting an oracle database and explain each?
2. Give the three modes of shutting down an Oracle database and explain each?
3. Who can start and stop an Oracle database
4. How do you create a user account in an Oracle database?
5. How do you delete a user account in an Oracle database?
6. Explain the difference between an Oracle database and Oracle instance?
7. Name three physical objects that can be seen from the OS layer of Database Server?
8. Name two Oracle OS layer processes?
9. What is the utility to write an Oracle database to an OS layer file?
10. What is the utility to read an Oracle database to an OS layer file?

Answers:

1. Give the three modes of starting an oracle database and explain each?

Startup nomount – The pfile or initfile is read and memory realm is started.

Startup mount –The controlfile is read and files verified.

Startup –The datafiles are opened in read/write mode and the database is open in read/write mode.

2. Give the three modes of shutting down an Oracle database and explain each?

Shutdown – All new connections are refused, current connections are maintained until the users log off, and once all user connections are completed the database shuts down.

Shutdown immediate – All new connections are refused, all current connection activities are rolled back and disconnected, the database shuts down.

Shutdown abort – All connections are disconnected without roll back and the database shuts down.

3. Who can start and stop an Oracle database?

– The SYS user or any user with sysdba privileges can shutdown an Oracle database.

4. How do you create a user account in an Oracle database?

– Create user ‘username’ identified by ‘password’;

5. How do you delete a user account and all objects owned by that user in an Oracle database?

– Drop user ‘username’ cascade;

6. Explain the difference between an Oracle database and Oracle instance?

-Oracle database includes all of the physical objects of an Oracle environment which reside at the OS layer.

-Oracle Instance is the memory realm and OS processes of the Oracle environment.

7. Name three physical objects that can be seen from the OS layer of Database Server?

-controlfiles
-datafiles
-tempfiles
-redo logs
-archive redologs

8. Name two Oracle OS layer processes?

-PMON
-SMON
-ARCN
-MMON
-MMNL
-MMAN
-LGWR
-CKPT

9. What is the utility to write an Oracle database to an OS layer file?

-EXP or export in any version of Oracle.
-EXPDP or export data pump in Oracle 10g or higher

10. What is the utility to read an Oracle database to an OS layer file?

-IMP or import in any version of Oracle.
-IMPDP or import data pump in Oracle 10g or higher

Larry J. Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com