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. A ___________ must not contain a repeating group .






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






4. 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 ____.






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






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






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






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






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






10. 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.






11. A ______ attribute can have only one value.






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






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






14. ____ yields better performance.






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






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






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






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






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






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






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






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






23. 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 ____.






24. Another word for existence-independent is ____.






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






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






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






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






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






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






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






32. Data redundancy produces ____.






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






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






35. 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.






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






37. 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.






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






39. ________ cannot be further subdivided.






40. 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.






41. 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.






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






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






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






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






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






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






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






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