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






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






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






4. ________ cannot be further subdivided.






5. Data redundancy produces ____.






6. 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 ____.






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






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






9. ____ yields better performance.






10. 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.






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






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






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






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






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






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






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






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






19. 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.






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






21. 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.






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






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






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






25. 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 ____.






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






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






28. 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.






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






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






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






32. 1NF - 2NF - and 3NF are _____.






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






34. A ______ attribute can have only one value.






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






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






37. 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.






38. 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.






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






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






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






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






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






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






45. Improving ___ leads to more flexible queries.






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






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






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






49. Another word for existence-independent is ____.






50. 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.