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






2. 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.






3. An ERM is not dependent on the ____________.






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






5. 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 ____.






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






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






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






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






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






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






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






13. ____ yields better performance.






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






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






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






17. 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.






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






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






20. 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.






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






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






23. A ______ attribute can have only one value.






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






25. 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.






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






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






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






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






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






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






32. Data redundancy produces ____.






33. 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.






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






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






36. Improving ___ leads to more flexible queries.






37. ________ cannot be further subdivided.






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






39. Another word for existence-independent is ____.






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






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






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






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






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






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






46. 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.






47. 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 ____.






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






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






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