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






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






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






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






5. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






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






12. 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.






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






14. 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 ____.






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






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






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






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






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






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






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






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






23. 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.






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






25. Another word for existence-independent is ____.






26. ____ yields better performance.






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






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






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






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






31. An ERM is not dependent on the ____________.






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






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






34. 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.






35. Data redundancy produces ____.






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






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






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






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






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






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






42. 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.






43. 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 ____.






44. 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.






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






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






47. 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.






48. A ___________ must not contain a repeating group .






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






50. A ______ attribute can have only one value.