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. 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.






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






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






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






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






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






7. An ERM is not dependent on the ____________.






8. Data redundancy produces ____.






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






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






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






12. 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.






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






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






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






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






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






18. 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.






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






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






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






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






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






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






25. A ___________ must not contain a repeating group .






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






27. 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.






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






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






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






31. 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.






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






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






34. 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.






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






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






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






38. Improving ___ leads to more flexible queries.






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






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






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






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






43. ________ cannot be further subdivided.






44. Another word for existence-independent is ____.






45. ____ yields better performance.






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






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






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






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






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