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. 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.






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






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






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






6. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






12. 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 ____.






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






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






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






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






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






18. Improving ___ leads to more flexible queries.






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






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






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






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






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






24. ____ yields better performance.






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






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






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






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






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






30. An ERM is not dependent on the ____________.






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






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






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






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






35. 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.






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






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






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






39. 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.






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






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






42. Another word for existence-independent is ____.






43. 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.






44. 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 ____.






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






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






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






48. ________ cannot be further subdivided.






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






50. Data redundancy produces ____.