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. 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.






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






3. A ______ attribute can have only one value.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






22. ____ yields better performance.






23. 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.






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






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






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






27. 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.






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






29. 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.






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






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






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






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






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






35. Data redundancy produces ____.






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






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






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






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. Need not be stored physically in the data base.






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






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






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






44. 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.






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






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






47. Another word for existence-independent is ____.






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






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






50. 1NF - 2NF - and 3NF are _____.