Test your basic knowledge |

Data Modeling

Subject : it-skills
  • Answer 50 questions in 15 minutes.
  • Match each statement with the correct term.

1. A table where all attributes are dependent on the primary key are independent of each other - and no row contains two or more multivalued facts about an entity - is said to be in ____.

2. Relationship strength depends on how the primary key of the related entity is formulated - while the relationship ____ depends on how the business rule is written.

3. A ___ derives its name from the fact that a group of multiple entries of the same type can exist for any single key attribute occurrence.

4. A ______ attribute can have only one value.

5. ____ yields better performance.

6. If a table has multiple candidate keys and one of those candidate keys is a composite key - the table can have ___ based on this composite candidate key - even when the primary key chosen is a single attribute.

7. The ___ refers to a specific table row as an entity instance.

8. An attribute that is part of a key is known as a ____ attribute.

9. Most designers consider the BCNF as a special case of the ____.

10. Complex ____ requirements may dictate data transformations - and they may expand the number of entities and attributes withing the design.

11. ______________database tables often lead to various data redundancy disasters in production databases.

12. Need not be stored physically in the data base.

13. An example of denormalization is using a ___ denormalized table to hold report data. This is required when creating a tabular report in which the columns represent data that is stored in the table as rows.

14. Dependencies can be identified with the help of a dependency _____.

15. A table where every determinant is a candidate key is said to be in ____.

16. If database tables are treated as though they were files in a file system - the ___ never has a chance to demonstrate its superior data-handling capabilities.

17. The associative entity is also known as a ___ entity.

18. In a ___ diagram - the arrows above the attribute indicate all desirable dependencies.

19. View the data as part of a table or collection of tables in which all key values must be identified.

20. _______ databases reflect the ever-growing demand for greater scope and depth in the data on which decision support systems increasingly rely.

21. Dependencies based on only a part of a composite primary key are called ___ dependencies.

22. In order to meet performance requirements - you may have to denormalize portions of the ________.

23. A ___ relationship exists when an association is maintained within a single entity.

24. A ____ relationship exists when three entities are associated.

25. The set of possible values for an attribute is a ____.

26. If an employee within an EMPLOYEE entity has a relationship with itself - that relationship is known as a ____ relationship.

27. A table that is in 2NF and contains no transitive dependencies is said to be in ___.

28. ________ cannot be further subdivided.

29. 1NF - 2NF - and 3NF are _____.

30. The word "entity" in the ER model corresponds to a _______.

31. Data redundancy produces ____.

32. From a system functionality point of view - ___ attribute values can be calculated when they are needed to write reports or invoices.

33. Improving ___ leads to more flexible queries.

34. From a structural point of view - ______ is better than 1NF

35. Depicts all dependencies found within a given table structure is known as a ______.

36. In order to meet ___ requirements - you may have to denormalize some portion of the database.

37. The price paid for increased performance through denormalization is a larger amount of ____.

38. A ___________ must not contain a repeating group .

39. A table is in BCNF if every determinant in the table is a ____________.

40. A ___ identifier is composed of more than one attribute.

41. Any attribute whose value determines other values within a row is called ____.

42. Another word for existence-independent is ____.

43. A talbe is in 4NF if it is 3NF and has no ________.

44. When a nonkey attribute is the determinate of a key attribute the table is in 3NF but not ____.

45. Data redundancies occur from ____ of data on every row entry.

46. A table that has all key attributes defined - has no repeating groups - and all its attributes are dependent on the primary key - is said to be in ____.

47. BCNF can be violated only if the table contains more than one ___ key.

48. A ___ attribute is one that cannot be subdivided.

49. The Crow's foot symbol with two parallel lines indicates ___ cardinality.

50. The existence of a(n) ___ relationship indicated that the minimum cardinality is at least 1 for the mandatory entity.