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Database Management Systems

1. Distinguish between TRUNCATE and DELETE2. Explain with examples :

a. Domain Integrity

b. Entity Integrityc. Referential Integrity3. Explain how security is implemented in RDBMS ?4. Explain some of the best practices that should be followed while

writing SQL Queries5. Distinguish between Horizontal View and Vertical View6. What is the difference between a candidate key and primary

key ?7. What are the disadvantages of the traditional file approach ?8. Suppose we have an employee table and a department table. Let

us say that we delete a department from the department table.

All the employee records that have the department will behaving entries of department that no longer exists in thedepartment table. How can we handle this ?For e.g., we may want to prevent deleting the department fromthe department table when there are employees working for thatdepartment.There are also other approaches to this problem. Can you explain?

9. Distinguish between an independent sub-query and correlatedsub-query ?

10. How can we speed up the execution of a query ? Explain

the mechanism used in the process to speed up execution of aquery ?

11. Explain what is a phantom record ?12. Explain the differences between a Batch Transaction

Processing (BTP) system and an On-line Transaction Processing(OLTP) System

13. What is a lock ? Explain the difference between a SharedLock and anExclusive Lock ?

14. What are the steps involved in the design of a database ?15. What is check-pointing ? How is it different from deferred

updates or immediate updates ?16. Distinguish between On-line Transaction Processing (OLTP)

and On-line Analytical Processing (OLAP) ?17. What is a Data Warehouse ? Why do we need it ? What

makes it different from a Data Mart ?18. Explain the properties of a transaction based system19. What are the issues with allowing multiple transactions to

occur at the same time ?

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20. Explain the difference between UNION Vs UNION ALL whenused in a query ?

21. Explain the difference between count(*) and count(columnname)

22. Distinguish between column constraint and table constraint

? Explain table constraint with an example ?23. There are the char and varchar2 datatypes in most Oracle.Explain the difference between these 2 types

24. What is normalization ? Why do we need to normalize tables ?25. Explain the steps in converting an un-normalized database to 3rd

normal form ?26. Explain with an example of how normalization eliminates

redundancy ?27. What is BCNF ? How do we convert a database that is in

3NF to BCNF ?28. What are the problems faced by a database that is in 2NF ?

29. What are the problems faced by a database that is in 1NF ?30. Explain with a example what is meant by functional

dependency ?31. Explain with a example what is meant by transitive

dependency ?32. Explain the merits and de-merits of normalization33. What is de-normalization ? Why do we need to de-

normalize a database ?34. Explain the differences between full functional dependency

and partial dependency with an example35. What is a self-referencing table ? Can you provide an

example of such a table ?36. Explain the hierarchy of data models ?37. Distinguish between Relational Model, Hierarchical Model

and Network Model. Can you name some commercial packagesfor the models ?

38. What is a super key ? Given an example of a super key39. What are the guidelines that we should follow when we

select a primary key ?40. Explain the types of relationships with examples : One to

One, One to Many, Many to One, Many to Many41. What is a derived attribute ? Give an example.

42. What are the main building blocks of the EntityRelationship (ER) model ?

43. Explain the difference between a database and a table44. Illustrate the difference ( with an example ) between

natural JOIN, equi JOIN and outer JOIN45. Explain what is a data dictionary ?46. Explain DDL, DML and DCL statements. Provide examples

of each category.

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47. What is the difference between the following terms :ON DELETE RESTRICT and ON DELETE CASCADE

48. What is a composite entity ? Give an example ? How do werepresent composite entities in a E-R diagram ?

49. What is a weak entity ? Give an example ? How do we represent

weak entities in a E-R diagram ?50. What is a recursive entity ? Give an example ? How do we

represent recursive entities in a E-R diagram ?51. What are the factors that influence the selection of a good

DBMS package?52. What is concurrency control and why is it important for a

database ?53. Distinguish between data and information54. Distinguish between top-down and bottom-up in database

design strategies55. What are business rules ? Explain with an example why

they are important for a database designer56. Explain the salient features of an Object Oriented DBMS ?57. Explain some of the merits and de-merits of OODBMS ?58. What are the chief responsibilities of a Database

Administrator (DBA) ?59. Distinguish between a composite attribute and a multi-

valued attribute60. Explain unary, binary and ternary relationships with

examples