# Data Modeling

Subject : it-skills
Instructions:
• Answer 50 questions in 15 minutes.
• If you are not ready to take this test, you can study here.
• Match each statement with the correct term.
• Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Refers to the level of detail represented by the values stored in a table's row

2. ________ cannot be further subdivided.

3. Normalization represents a micro view of the ___ within the ERD.

4. 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.

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

6. 1NF - 2NF - and 3NF are _____.

7. 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.

8. 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 ____.

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

10. A ___________ must not contain a repeating group .

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

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

13. Data redundancy produces ____.

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

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

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

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

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

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

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

21. A _____ entity is composed of the primary keys of each of the entities to be connected.

22. 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.

23. A ___ relationship exists when two entities are associated.

24. A ______ attribute can have only one value.

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

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

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

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

29. In the ERD - Cardinality is indicated using the ___ notation.

30. The following step occurs first in the process of building an ERD: create a __________ of the organization's description of operations.

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

32. 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.

33. A ___ entity has a primary key that is partially or totally derived from the parent entity in the relationship.

34. ____ yields better performance.

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

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

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

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

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

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

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

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

43. A ____ exists when there are functional dependencies such that Y is functionally dependent on X and Z is functionally dependent on Y - and X is the primary key.

44. In a real-world environment - changing granularity requirements might dictate changes in primary key selection - and those changes might ultimately require the use of ____ keys.

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

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

47. Another word for existence-independent is ____.

48. Improving ___ leads to more flexible queries.

49. The conflicts between design efficiency - ____________ - and processing speed are often resolved through compromised that include denormalization.

50. An ERM is not dependent on the ____________.