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






2. 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.






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






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






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






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






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






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






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






10. 1NF - 2NF - and 3NF are _____.






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






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






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






14. ____ yields better performance.






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






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






17. 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 ____.






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






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






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






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






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






23. 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.






24. Another word for existence-independent is ____.






25. Data redundancy produces ____.






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






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






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






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






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






31. A ___________ must not contain a repeating group .






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






33. 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 ____.






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






35. 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.






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






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






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






39. 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.






40. A ______ attribute can have only one value.






41. 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.






42. 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.






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






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






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






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






47. 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.






48. Improving ___ leads to more flexible queries.






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






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