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 MOST LIKELY DATA TYPE FOR A SURROGATE KEY IS ____.






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






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






4. Another word for existence-independent is ____.






5. 1NF - 2NF - and 3NF are _____.






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






7. 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 ____.






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






9. ________ cannot be further subdivided.






10. 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.






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






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






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






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






15. An ERM is not dependent on the ____________.






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






17. 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.






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






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






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






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






22. A ______ attribute can have only one value.






23. 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.






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






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






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






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






28. Data redundancy produces ____.






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






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






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






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






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






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






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






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






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






38. 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.






39. A ___________ must not contain a repeating group .






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






41. 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.






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






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






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






45. ____ yields better performance.






46. 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.






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






48. 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 ____.






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






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