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. ____ yields better performance.






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






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






4. ________ cannot be further subdivided.






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






6. A ___________ must not contain a repeating group .






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






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






9. 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.






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






11. 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.






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






13. 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.






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






15. 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.






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






17. Another word for existence-independent is ____.






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






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






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






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






22. 1NF - 2NF - and 3NF are _____.






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






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






25. 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 ____.






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






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






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






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






30. 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 ____.






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






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






33. Improving ___ leads to more flexible queries.






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






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






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






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






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






39. 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.






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






41. A ______ attribute can have only one value.






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






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






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






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






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






47. Data redundancy produces ____.






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






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






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