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. 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.






3. 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.






4. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






10. 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.






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






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






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






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






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






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






17. ____ yields better performance.






18. 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.






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






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






21. 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.






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






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






24. 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.






25. Another word for existence-independent is ____.






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






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






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






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






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






31. Improving ___ leads to more flexible queries.






32. ________ cannot be further subdivided.






33. A ___ relationship exists when two entities are associated.






34. A ___________ must not contain a repeating group .






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






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






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






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






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






40. 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.






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






42. 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 ____.






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






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






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






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






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






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






49. An ERM is not dependent on the ____________.






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