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. 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.






2. 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.






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






4. An ERM is not dependent on the ____________.






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






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






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






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






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






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






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






12. 1NF - 2NF - and 3NF are _____.






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






14. 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 ____.






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






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






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






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






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






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






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






22. ____ yields better performance.






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






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






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






26. ________ cannot be further subdivided.






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






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






29. Another word for existence-independent is ____.






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






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






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






33. 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.






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






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






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






37. A ______ attribute can have only one value.






38. A ___________ must not contain a repeating group .






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






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






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






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






43. Data redundancy produces ____.






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






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






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






47. 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.






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






49. 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.






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