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 can be identified with the help of a dependency _____.






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






3. 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.






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






5. 1NF - 2NF - and 3NF are _____.






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






7. 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.






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






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






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






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






12. 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.






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






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






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






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






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






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






19. Another word for existence-independent is ____.






20. Data redundancy produces ____.






21. A ______ attribute can have only one value.






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






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






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






25. 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.






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






27. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






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






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






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






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






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






40. ____ yields better performance.






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






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






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






44. 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.






45. ________ cannot be further subdivided.






46. 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.






47. A ___________ must not contain a repeating group .






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






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






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