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 ___ identifier is composed of more than one attribute.






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






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






4. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






13. 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 ____.






14. Another word for existence-independent is ____.






15. 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.






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






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






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






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






20. 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 ____.






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






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






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






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






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






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






27. 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.






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






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






30. ________ cannot be further subdivided.






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






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






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






34. 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.






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






36. ____ yields better performance.






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






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






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






40. An ERM is not dependent on the ____________.






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






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






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






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






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






46. A ___________ must not contain a repeating group .






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






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






49. 1NF - 2NF - and 3NF are _____.






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