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. 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.






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






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






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






5. 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.






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






7. 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.






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






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






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






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






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






14. 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.






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






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






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






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






19. A ___________ must not contain a repeating group .






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






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






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






23. Data redundancy produces ____.






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






25. 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 ____.






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






27. 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.






28. ____ yields better performance.






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






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






31. An ERM is not dependent on the ____________.






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






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






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






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






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






37. Another word for existence-independent is ____.






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






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






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






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






42. Improving ___ leads to more flexible queries.






43. A ______ attribute can have only one value.






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






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






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






47. 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 ____.






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






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






50. 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.