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






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






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






4. 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.






5. An ERM is not dependent on the ____________.






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






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






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






9. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






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






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






17. 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 ____.






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






19. 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.






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






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






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






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






24. A ______ attribute can have only one value.






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






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






27. 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 ____.






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






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






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






31. Data redundancy produces ____.






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






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






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






35. ________ cannot be further subdivided.






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






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






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






39. 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.






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






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






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






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






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






45. 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.






46. 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.






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






48. Improving ___ leads to more flexible queries.






49. ____ yields better performance.






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