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






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






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






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






5. ____ yields better performance.






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






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






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






9. 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.






10. 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.






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






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






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






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






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






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






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






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






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






20. Improving ___ leads to more flexible queries.






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






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






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






24. 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.






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






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






27. 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.






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






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






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






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






32. 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.






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






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






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






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






37. ________ cannot be further subdivided.






38. 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 ____.






39. 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.






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






41. Another word for existence-independent is ____.






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






43. 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.






44. An ERM is not dependent on the ____________.






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






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






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






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






49. Data redundancy produces ____.






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