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






3. 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.






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






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






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






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






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






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






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






11. 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.






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






13. 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.






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






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






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






17. A ___________ must not contain a repeating group .






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






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






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






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






22. ____ yields better performance.






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






24. 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.






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






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






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






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






29. 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.






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






31. Improving ___ leads to more flexible queries.






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






33. Data redundancy produces ____.






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






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






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






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






39. Another word for existence-independent is ____.






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






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






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






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






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






45. An ERM is not dependent on the ____________.






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






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






48. A ______ attribute can have only one value.






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






50. ________ cannot be further subdivided.