Oracle Interview Questions

SQL Interview Questions:-

1)      What are Data Base Objects? What are they?

2)      What is a View? And what are Advantages of View?

3)      What is Synonym? And What  are its Advantages

4)      What is Difference between View and Synonym?

5)      What is Difference between Delete and Truncate Commands?

6)      If you delete Base tables, what is the Status of View and Synonym?

7)      What is Primary Key? And Foreign Key?

8)      What is ON DELETE CASCADE Clause?

9)      What is Difference between Sub query and co-related sub query?

10)   What are Different Data types?

11)    What is Difference between INSTR() AND SUBSTR()

12)   What is difference between TRANSLATE() AND REPLACE()

13)   What is difference between IN AND EXISTS?

14)   What is difference between TRUNC () AND ROUND ()?

15)   What is INDEX? How many types of INDEX?

16)   What is Cluster?

17)   What is difference between Cluster and Index?

18)   What is sequence?

19)   What is a JOIN? How many Types of Joins are there?

20)   What is difference between UNIQUE and PRIMARY KEY?

21)   What is the difference between NOT NULL and UNIQUE?

22)   What is the use of ORDER BY Clause?

23)   What is firing sequence of ORDER BY, GROUP BY, HAVING and WHERE Clause?

24)   What is difference between DECODE() and CASE?

Queries:-

1)      Write a query for deleting the duplicate records from a table.

2)      Write a query to findout nth maximum salary.

3)      Write query to findout 2^nd max salary.

PL/SQL Interview Questions:-

1)      What is a Cursor? What are different types of Cursors?

2)      What are Cursor Attributes?

3)      What is Ref-Cursor?

4)      What is difference between Cursor and Ref-Cursor?

5)      What are the Use of FOR UPDATE OF and WHERE CURRENT OF Clause?

6)      What is Cursor for Loop? And what is the difference between cursor and for loop cursor?

7)      What is Exception?

8)      What are Different types of Exceptions?

9)      What are user Predefined Exceptions

10)   What is the difference between RAISE_APPLICATION_ERROR and PRAGMA EXCEPTION_INIT ()?

11)   What is PRAGMA? AND how many Types of Pragmas Available Explain?

12)   What is Mutating Error? AND when will get this error and what is the resolution of this error?

13)   What is trigger?

14)   How Many Types of Triggers are there?

15)   What is meant by INSTEAD OF TRIGGER? What are its Advantages

16)   What is difference between Procedure and trigger?

17)   What is difference between Function and trigger?

18)   What is difference between Procedure and Function?

19)   What is difference between Procedure and Package?

20)    What is PL/SQL table and what are different Types of PL/SQL TABLES types?

21)   What is Difference between %TYPE and %ROWTYPE?

22)   What is meant by Dynamic SQL?

23)   What is BULK COLLECT?