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 set of possible values for an attribute is a ____.






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






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






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






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






6. A ______ attribute can have only one value.






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






8. 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.






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






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






11. 1NF - 2NF - and 3NF are _____.






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






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






14. Improving ___ leads to more flexible queries.






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






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






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






18. 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.






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






20. An ERM is not dependent on the ____________.






21. 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.






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






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






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






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






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






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






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






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






30. Data redundancy produces ____.






31. Another word for existence-independent is ____.






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






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






34. ____ yields better performance.






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






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






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






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






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






40. 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 ____.






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






42. 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 ____.






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






44. 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.






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






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






47. A ___________ must not contain a repeating group .






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






49. Depicts all dependencies found within a given table structure is known as a ______.






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