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






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






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. An ERM is not dependent on the ____________.






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






6. 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.






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






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






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






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






11. Another word for existence-independent is ____.






12. A ______ attribute can have only one value.






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






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






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






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






17. ________ cannot be further subdivided.






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






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






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






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






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






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






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






25. 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.






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






27. A ___________ must not contain a repeating group .






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






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






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






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






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






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






34. Data redundancy produces ____.






35. 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.






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






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






38. 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.






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






40. Improving ___ leads to more flexible queries.






41. ____ yields better performance.






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






43. 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.






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






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






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






47. 1NF - 2NF - and 3NF are _____.






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






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






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