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. 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.






2. ____ yields better performance.






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






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






5. Another word for existence-independent is ____.






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






7. 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.






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






9. 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.






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






11. 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.






12. An ERM is not dependent on the ____________.






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






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






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






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






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






18. 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.






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






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






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






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






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






24. 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 ____.






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






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






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






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






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






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






31. A ___________ must not contain a repeating group .






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






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






34. 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.






35. ________ cannot be further subdivided.






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






37. 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.






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






39. Data redundancy produces ____.






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






41. 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.






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






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






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






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






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






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






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






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






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