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






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






3. 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.






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






5. 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.






6. A ______ attribute can have only one value.






7. A ___________ must not contain a repeating group .






8. 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.






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






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






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






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






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






14. Data redundancy produces ____.






15. ________ cannot be further subdivided.






16. 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 ____.






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






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






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






20. 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.






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






22. 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.






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






24. 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.






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






26. 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.






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






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






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






30. Another word for existence-independent is ____.






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






32. An ERM is not dependent on the ____________.






33. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






48. 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.






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






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