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






3. 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.






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






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






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






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






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






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






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






11. 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.






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






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






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






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






16. ________ cannot be further subdivided.






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






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






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. 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.






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






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






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






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






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






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






27. 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.






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






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






30. 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.






31. A ______ attribute can have only one value.






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






33. An ERM is not dependent on the ____________.






34. 1NF - 2NF - and 3NF are _____.






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






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






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






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






39. Another word for existence-independent is ____.






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






41. 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 ____.






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






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






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






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






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






47. Improving ___ leads to more flexible queries.






48. 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.






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






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