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






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






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






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






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






7. ____ yields better performance.






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






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






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






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






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






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






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






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






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






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






19. Improving ___ leads to more flexible queries.






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






22. 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.






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






24. 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.






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






26. A ______ attribute can have only one value.






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






28. 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.






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






30. Data redundancy produces ____.






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






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






33. Another word for existence-independent is ____.






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






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






36. 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.






37. ________ cannot be further subdivided.






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






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






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






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






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






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






44. 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.






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






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






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






48. A ___________ must not contain a repeating group .






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






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