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






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






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






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






6. A ___________ must not contain a repeating group .






7. A ______ attribute can have only one value.






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






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






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






11. 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.






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






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






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






15. 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 ____.






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






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






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






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






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






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






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






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






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






25. Another word for existence-independent is ____.






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






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






28. 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.






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






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






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






32. Data redundancy produces ____.






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






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






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






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






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






38. 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.






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






40. ____ yields better performance.






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






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






43. 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.






44. Improving ___ leads to more flexible queries.






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






46. 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.






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






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






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






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