(Paper) Recent RDBMS SQL Interview Questions and Answers

What is the advantage to use trigger in your PL?
Triggers are fired implicitly on the tables/views on which they are created. There are various advantages of using a trigger. Some of them are:

• Suppose we need to validate a DML statement(insert/Update/Delete) that modifies a table then we can write a trigger on the table that gets fired implicitly whenever DML statement is executed on that table.
  

• Another reason of using triggers can be for automatic updation of one or more tables whenever a DML/DDL statement is executed for the table on which the trigger is created.
  

• Triggers can be used to enforce constraints. For eg : Any insert/update/ Delete statements should not be allowed on a particular table after office hours. For enforcing this constraint Triggers should be used.
  

• Triggers can be used to publish information about database events to subscribers. Database event can be a system event like Database startup or shutdown or it can be a user even like User loggin in or user logoff.
  

SQL Interview Questions and Answers :

What is the difference between oracle,sql and sql server ?

• Oracle is based on RDBMS.

• SQL is Structured Query Language.

• SQL Server is another tool for RDBMS provided by MicroSoft.
  

why you need indexing ? where that is stroed and what you mean by schema object? For what purpose we are using view?
We cant create an Index on Index.. Index is stoed in user_index table.Every object that has been created on Schema is Schema Object like Table,View etc.If we want to share the particular data to various users we have to use the virtual table for the Base table...So tht is a view.

indexing is used for faster search or to retrieve data faster from various table. Schema containing set of tables, basically schema means logical separation of the database. View is crated for faster retrieval of data. It's customized virtual table. we can create a single view of multiple tables. Only the drawback is..view needs to be get refreshed for retrieving updated data.

FOR ORACLE PLACEMENT PAPERS AND HR AND TECHNICAL INTERVIEW QUESTION
Oracle conducted test for freshers at bangalore in their campus (near Diary circle).
Question paper consists of 60 questions.
30 - english and Aptitude
30 - SQL,C,C++,JAVA

English:
Analogy questions around ( You can refer to GRE book)
Fill the sentence with appropriate word..(multiple choices given)
Sentence correction..

Aptitude:
Arithmetic questions..
Some of the questions:

Q: 1/3th of the passengers gotdown at first stop and 30 people got into the bus, 1/4th of the passengers gotdown at second stop and 12 people got into the bus. in last stop 84 people got down from the bus. What is the initial capacity of the bus?

Q: One person is running around a 180 sq yard filed, first 1/4 his speed was 10KMPH second 1/4 20KMPH third 1/4 30 KMPH and the fourth 1/4 40 KMPH. what is the average speed?

NOTE: There was a question on milk ,water ratio..

Logical Deductions..
Q: is x+y a prime?
a. x is prime
b. y is prime
options: 
1. only "a" correct 
2. only "b" correct 
3. both are correct
4. both are wrong.

C,C++,JAVA

Q: There were 2 or 3 C programs and the question is to point error in the program or to predict the answer

Q:Which one of the following is not a storage type:
1. static 2. register 3. stack 4.auto
answer: stack

Q:what is the type of the second parameter of fopen() function?

Q:Which of the following is correct about constructor?
OPTIONS: 1.void type 2. return nothing
answer 2

Q:how do we store a constant value in java?
multiple choices given..
answer: using "final"

SQL:
Be thorough with SQL, PL/SQL

QUESTIONS ASKED ARE LIKE - A QUERY IS GIVEN. TELL WHETHER ITS RIGHT OR WRONG

Q: create table..; {table creation query)
Roll back;
what will be the output?
options ..

" "INFOSYS OR ORACLE PLACEMENT PAPERS CAN BE CLEARED EASILY IF STUDENTS SPEND ABOUT A MONTH ON APTITUDE AND GENERAL ENGLISH. ALSO DECIDE YOUR LANGUAGE OF EXPERTISE AND BE PREPARED TO ANSWER GENERAL QUESTIONS IN NEARLY ALL THE DOMAINS FOR WHICH THE COMPANY IS GOING TO RECRUIT. PRACTISE OR TRAIN FOR THE HR INTERVIEW." "

16. What is the output of the following program
class questionC {
int a;
public int c;
private int c;

void setc(int i) {
c = i;
}

int getc() {
return c;
}
}

class printQuestionC {
public static void main ( String args[ ] ) {
questionC qc = new questionC( );
qc.a = 10;
qc.b = 20;
qc.c = 100;
qc.b = qc.a + qc.c;
System.out.println ( "a, b and c : " + qc.a + ", " + qc.b + ", " + qc.getc());
}
}

(A) a, b and c : 10, 20, 100
(B) a, b and c : 10, 110, 100
(C) a, b and c : 10, 110,
(D) The code does not compile.

17. Which of the following is not true about serialization
(A) Only an object that implements the Serializable interface can be saved and restored
(B) The Serializable interface defines no members
(C) transient variables can be saved by the serialization facilities
(D) static variables are not saved by the serialization facilities

18. What is the output of the following program ?
class Promote {
public static void main ( String args[ ] ) {
byte b 42;
char c = 'a';
short s = 1-24;
int i = 50000;
float f = 5.67 f;
double d = .1234;
double resuot = (f * b) + (i / c) - (d * s);
System.out.println("Result = " + result);
}
}
(A) The code does not compile.
(B) The final result of the expression is a double
(C) The final result of the expression is a float
(D) The final result of the expression is an int

19. Consider the following Java Code
public class Alias {
int i;
Alias(int ii) { i = ii; }
public static void main ( String [ ] args ) {
Alias x = new Alias(7);
Alias1 y = x;
System.out.println("x : " + x.i);
System.out.println("y : " + y.i);
x.i++;
System.out.println("x : " + x.i);
System.out.println("y : " + y.i);
}
}
What will be the output ?
(A) The code does not compile
(B) The code compiles but gives runtime exception
(C) x = 7
y = 7
x = 8
y = 7
(D) x = 7
y = 7
x = 8
y = 8