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 ____ 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.






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






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






4. A ______ attribute can have only one value.






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






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






7. 1NF - 2NF - and 3NF are _____.






8. Data redundancy produces ____.






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






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






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






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






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






15. 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 ____.






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






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






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






19. 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.






20. ________ cannot be further subdivided.






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






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






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






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






25. Another word for existence-independent is ____.






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






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






28. Improving ___ leads to more flexible queries.






29. ____ yields better performance.






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






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






32. A ___________ must not contain a repeating group .






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






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






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






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






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






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






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






40. 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.






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






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






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






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






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






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






48. 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.






49. 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.






50. An ERM is not dependent on the ____________.