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. According to naming conventions described in Chapter 2 - ___ would be the best name for a column representing the charges per hour in a table named JOB.






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






3. Another word for existence-independent is ____.






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






5. 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.






6. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






23. A ______ attribute can have only one value.






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






25. 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.






26. ____ yields better performance.






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






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






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






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






31. 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.






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






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






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






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






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






37. ________ cannot be further subdivided.






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






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






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






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






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






43. 1NF - 2NF - and 3NF are _____.






44. An ERM is not dependent on the ____________.






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






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






47. Data redundancy produces ____.






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






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






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