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. ________ cannot be further subdivided.






2. 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.






3. 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.






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






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






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






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






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






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






10. 1NF - 2NF - and 3NF are _____.






11. A ______ attribute can have only one value.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






28. Improving ___ leads to more flexible queries.






29. 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 ____.






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






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






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






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






34. 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.






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






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






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






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






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






40. An ERM is not dependent on the ____________.






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






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






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






44. 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.






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






46. ____ yields better performance.






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






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






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






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