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. 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.






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






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






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






5. ____ yields better performance.






6. A ___________ must not contain a repeating group .






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






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






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






10. Another word for existence-independent is ____.






11. An ERM is not dependent on the ____________.






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






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






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






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






16. ________ cannot be further subdivided.






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






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






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






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






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






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






23. 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.






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






25. 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 ____.






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






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






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






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






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






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






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






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






34. Data redundancy produces ____.






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






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






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






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






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






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






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






42. 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.






43. A ______ attribute can have only one value.






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






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






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






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






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






49. 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.






50. 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.