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






2. 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.






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






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






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






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






7. Another word for existence-independent is ____.






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






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






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






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






12. A ___________ must not contain a repeating group .






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






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






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






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






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






18. 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.






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






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






21. Improving ___ leads to more flexible queries.






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






23. An ERM is not dependent on the ____________.






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






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






26. 1NF - 2NF - and 3NF are _____.






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






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






29. A ______ attribute can have only one value.






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






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






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






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






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






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






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






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






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






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






40. ________ cannot be further subdivided.






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






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






43. 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.






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






45. 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.






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






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. A ____ relationship exists when three entities are associated.






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






50. ____ yields better performance.