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.
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