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






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






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






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






5. 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.






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






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






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






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






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






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






12. Another word for existence-independent is ____.






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






14. A ___________ must not contain a repeating group .






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






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






17. 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.






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






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






21. ________ cannot be further subdivided.






22. 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.






23. 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 ____.






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






25. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






43. 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 ____.






44. 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.






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






46. Data redundancy produces ____.






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






48. ____ yields better performance.






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






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