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






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






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






4. ________ cannot be further subdivided.






5. Data redundancy produces ____.






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






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






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






9. 1NF - 2NF - and 3NF are _____.






10. 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.






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






12. An ERM is not dependent on the ____________.






13. Improving ___ leads to more flexible queries.






14. 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 ____.






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






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






17. 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.






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






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






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






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






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






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






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






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






26. 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.






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






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






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






30. 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.






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






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






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






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






35. 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.






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






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






39. 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.






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






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






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






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






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






45. ____ yields better performance.






46. A ___________ must not contain a repeating group .






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






48. 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.






49. A ______ attribute can have only one value.






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