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

2. 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.

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

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

5. Another word for existence-independent is ____.

6. 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.

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

8. Refers to the level of detail represented by the values stored in a table's row

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

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

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

12. 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 ____.

13. Data redundancy produces ____.

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

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

16. THE MOST LIKELY DATA TYPE FOR A SURROGATE KEY IS ____.

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

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

19. 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.

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

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

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

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

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

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

26. An ERM is not dependent on the ____________.

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

28. If you have three different transitive dependencies - ___ different determinants exist.

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

30. 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.

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

32. According to naming conventions described in Chapter 2 - ___ would be the best name for a column representing the charges per hour in a table named JOB.

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

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

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

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

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

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

39. 1NF - 2NF - and 3NF are _____.

40. 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.

41. ________ cannot be further subdivided.

42. 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.

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

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

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

46. __________ is a process to help reduce the likelihood of data anomalies.

47. 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 ____.

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

49. A ___________ must not contain a repeating group .

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