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. Need not be stored physically in the data base.






2. 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 ____.






3. 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.






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






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






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






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






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






9. 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.






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






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






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






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






15. Improving ___ leads to more flexible queries.






16. A ______ attribute can have only one value.






17. 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.






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






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






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






21. Another word for existence-independent is ____.






22. Data redundancy produces ____.






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






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






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






26. ________ cannot be further subdivided.






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






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






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






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






31. 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.






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






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






34. 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.






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






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






37. An ERM is not dependent on the ____________.






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






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






40. ____ yields better performance.






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






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






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






44. A ___________ must not contain a repeating group .






45. 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 ____.






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






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






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






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






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