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






2. 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.






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






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






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






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






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






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






9. 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.






10. ____ yields better performance.






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






12. The following step occurs first in the process of building an ERD: create a __________ of the organization's description of operations.






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






14. 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.






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






16. Another word for existence-independent is ____.






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






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






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






20. The existence of a(n) ___ relationship indicated that the minimum cardinality is at least 1 for the mandatory 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. BCNF can be violated only if the table contains more than one ___ key.






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






25. Improving ___ leads to more flexible queries.






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






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






28. Data redundancy produces ____.






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






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






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






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






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






34. 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.






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






36. 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.






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






38. 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.






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






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






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






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






44. An ERM is not dependent on the ____________.






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






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






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






48. A ___________ must not contain a repeating group .






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






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