Oracle interview questions

1) What are the various databases you have worked with ?

Oracle , SQl server , MySql are the mostly used , but be prepared for questions on other databases if you are going to say u have worked on others  besides oracle .

2) what is sql and what is PL/SQL ?

SQL – structured query language which has a  a single line executable statement .

PL/SQL a super set of SQL enables a procedural langaue model where we can write multiple lines of SQL statements as a block.

3) how do you select the second largest salary from a table ?

using a rank function .

4) what is normalization ?

The process of decomposing tables to eliminate data redundancy is called Normalization. There are five normal forms . Google around for this .one of the irritating interview questions

5) difference between char and varchar ?

6) what is a trigger and why you need it , this can also be done bywriting the trigger code as a seperate function ?

7) what is a cursor and have you heard of REF – cursor ?

8) what is a index and when u need this . what are the different types ?

9) Difference between drop and truncate ?

10) what are the DML and DDL commands ?

11) what is a view and can we create a trigger for a view ?

12) do u know stored procedure, packages,functions ?

13) commit and rollback , savepoint ?

14) what is a package and what is UTIL ?

Package is used to group related objects like procedures , functions under one roof . UTIL is a package provided by oracle to extract or load file in oracle .


15) what  is decode and what is varray ?

Decode is a function which enables us to use it like IF >> THEN >> ELSE statement.


decode (’empname’,1000,’rich’



the above code will check empname column and will return as rich if the value is 1001 and return as poor if the value is 101 .


16)how to catch exception errors in oracle ?

In the exception block , use raise_application_error(errcode,’err message’) for user defined exceptions .


These are some of the important questions when answered the interviewer believes that the resource can be trained and deployed . Happy job hunting