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. 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.






2. 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.






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






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






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






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






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






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






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






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






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






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






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






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






16. 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 ____.






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






18. 1NF - 2NF - and 3NF are _____.






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






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






21. Improving ___ leads to more flexible queries.






22. 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.






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






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






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






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






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. 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.






29. ____ yields better performance.






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






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






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






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






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






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






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






37. An ERM is not dependent on the ____________.






38. ________ cannot be further subdivided.






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






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






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






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






44. 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 ____.






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






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






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






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






49. 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.






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