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






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






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






4. ________ cannot be further subdivided.






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






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






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






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






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






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






11. 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.






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






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






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






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






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






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






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






19. ____ yields better performance.






20. 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.






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






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






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






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






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






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






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






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






29. Improving ___ leads to more flexible queries.






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






31. Data redundancy produces ____.






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. A ______ attribute can have only one value.






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






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






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






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






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






39. 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.






40. An ERM is not dependent on the ____________.






41. Another word for existence-independent is ____.






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






43. 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.






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






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






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






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






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






49. A ___________ must not contain a repeating group .






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