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 has all key attributes defined - has no repeating groups - and all its attributes are dependent on the primary key - is said to be in ____.






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






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






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






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






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






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






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






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






10. 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.






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






12. Improving ___ leads to more flexible queries.






13. 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 ____.






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






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






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






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






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






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






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






21. ____ yields better performance.






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






23. 1NF - 2NF - and 3NF are _____.






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






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






26. 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.






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






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






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. A ____ relationship exists when three entities are associated.






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






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






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






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






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






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






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






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






39. ________ cannot be further subdivided.






40. A ______ attribute can have only one value.






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






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






43. Another word for existence-independent is ____.






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






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






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






47. An ERM is not dependent on the ____________.






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






49. Data redundancy produces ____.






50. 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.