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






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






3. 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 ____.






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






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






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






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






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






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






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






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






12. Data redundancy produces ____.






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






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






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






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






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






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






19. A ______ attribute can have only one value.






20. Another word for existence-independent is ____.






21. 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.






22. ____ yields better performance.






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






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






25. 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.






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






27. Improving ___ leads to more flexible queries.






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






29. 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.






30. 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.






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






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






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






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






35. 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.






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






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






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






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






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






41. An ERM is not dependent on the ____________.






42. ________ cannot be further subdivided.






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






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






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






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






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






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






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






50. 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.