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 two entities are associated.






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






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






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






6. A ___________ must not contain a repeating group .






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






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






9. Improving ___ leads to more flexible queries.






10. 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.






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






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






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






14. 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 ____.






15. Data redundancy produces ____.






16. The existence of a(n) ___ relationship indicated that the minimum cardinality is at least 1 for the mandatory entity.






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






18. 1NF - 2NF - and 3NF are _____.






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






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






21. A ______ attribute can have only one value.






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






23. An ERM is not dependent on the ____________.






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






25. 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.






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






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






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






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






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






31. 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.






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






33. 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.






34. Another word for existence-independent is ____.






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






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






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






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






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






40. 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.






41. ________ cannot be further subdivided.






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






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






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






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






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






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






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