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 the ERD - Cardinality is indicated using the ___ notation.






2. 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 ____.






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 ______ attribute can have only one value.






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






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






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






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






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






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






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






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






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






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






16. Another word for existence-independent is ____.






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






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






19. Data redundancy produces ____.






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






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






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






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






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






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






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






27. 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.






28. ____ yields better performance.






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






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






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






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






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






34. 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.






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






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






37. An ERM is not dependent on the ____________.






38. 1NF - 2NF - and 3NF are _____.






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






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






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






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






43. 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.






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






45. 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.






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






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






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






50. Improving ___ leads to more flexible queries.