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. Data redundancy produces ____.






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






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






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






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






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






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






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






10. ________ cannot be further subdivided.






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






12. Depicts all dependencies found within a given table structure is known as a ______.






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






14. 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.






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






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






17. An ERM is not dependent on the ____________.






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






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






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






21. 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 ____.






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






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






24. Another word for existence-independent is ____.






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






26. 1NF - 2NF - and 3NF are _____.






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






28. 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 ____.






29. A ______ attribute can have only one value.






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






31. 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.






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






33. 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.






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






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






36. 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.






37. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






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






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






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






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






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






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