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






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






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






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






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






6. 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.






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






8. A ___________ must not contain a repeating group .






9. 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.






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






11. Another word for existence-independent is ____.






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






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






14. 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.






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






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






17. ____ yields better performance.






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






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






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






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






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






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






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 set of possible values for an attribute is a ____.






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






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






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






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






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






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






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






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






34. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






42. 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.






43. ________ cannot be further subdivided.






44. An ERM is not dependent on the ____________.






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






46. 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.






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






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






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






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