Oracle DBA Interview Questions and Answers-1

                                      Page-1

1:  Which are the default passwords of SYSTEM/SYS?
A: MANAGER / CHANGE_ON_INSTALL

2 : How can you execute a script file in SQLPLUS?
A: To execute a script file in SQLPlus, type @ and then the file name.

3: Where can you find official Oracle documentation?
A: tahiti.oracle.com

4: What is the address of the Official Oracle Support?
A: metalink.oracle.com or support.oracle.com

5: What file will you use to establish Oracle connections from a remote client?
A: tnsnames.ora

6: How can you check if the database is accepting connections?
A: lsnrctl status or lsnrctl services

7: Which log would you check if a database has a problem?
A: Alert log

8:  Name three clients to connect with Oracle, for example, SQL Developer:
A: SQL Developer, SQL-Plus, TOAD, dbvisualizer, PL/SQL Developer… There are several, but an
     experienced dba should know at least three clients.

9: How can you check the structure of a table from sqlplus?
A: DESCRIBE or DESC

10: What command will you start to run the installation of Oracle software on Linux?
A:  runInstaller


11: Explain the differences between PFILE and SPFILE
A: A PFILE is a Static, text file that initialices the database parameter in the moment that it’s started. If you
     want to modify parameters in PFILE, you have to restart the database.
    A SPFILE is a dynamic, binary file that allows you to overwrite parameters while the database is already
    started (with some exceptions)

12: In which Oracle version was Data Pump introduced?
A:  Oracle 10g

13: Say two examples of DML, two of DCL and two of DDL
A: DML: SELECT, INSERT, UPDATE, DELETE, MERGE, CALL, EXPLAIN PLAN, LOCK TABLE
     DDL: CREATE, ALTER, DROP, TRUNCATE, COMMENT, RENAME
     DCL: GRANT, REVOKE

14: You want to save the output of an Oracle script from sqlplus. How would you do it?
A: spool script_name.txt
     select * from your_oracle_operations;
     spool off;

15: How can you view all the users account in the database?
A: SELECT USERNAME FROM DBA_USERS;

<<< Page-2 >>>