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






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






3. 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.






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






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






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






7. 1NF - 2NF - and 3NF are _____.






8. 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.






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






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






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






12. ________ cannot be further subdivided.






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






14. A ___________ must not contain a repeating group .






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






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






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






18. 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.






19. ____ yields better performance.






20. 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.






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






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






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






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






25. Another word for existence-independent is ____.






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






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






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






29. 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.






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






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






32. 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.






33. An ERM is not dependent on the ____________.






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






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






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






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






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






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






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






41. Data redundancy produces ____.






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






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






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






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






46. 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.






47. A ______ attribute can have only one value.






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






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






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