Test your basic knowledge |

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






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






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






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






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






6. 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.






7. A ___________ must not contain a repeating group .






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






9. 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.






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






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






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






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






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






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






16. Another word for existence-independent is ____.






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






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






19. 1NF - 2NF - and 3NF are _____.






20. 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 ____.






21. ____ yields better performance.






22. ________ cannot be further subdivided.






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






24. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






31. 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.






32. 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.






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






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






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






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






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






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






39. For most business transactional databases - we should normalize relations into ____.






40. 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 ____.






41. Data redundancy produces ____.






42. A ______ attribute can have only one value.






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






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






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






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






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






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






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






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