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. 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.






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






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






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






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






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






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






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






9. 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 ____.






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






11. 1NF - 2NF - and 3NF are _____.






12. Another word for existence-independent is ____.






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






14. ____ yields better performance.






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






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






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






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






19. 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.






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






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






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






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






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






26. 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.






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






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






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






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






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






32. 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 ____.






33. A ___________ must not contain a repeating group .






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






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






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






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






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






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






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






41. Improving ___ leads to more flexible queries.






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






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






44. A ______ attribute can have only one value.






45. ________ cannot be further subdivided.






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






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






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






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






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