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. Improving ___ leads to more flexible queries.






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






3. 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.






4. Data redundancy produces ____.






5. 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.






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






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






8. 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.






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






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






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






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






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






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






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






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






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






18. ____ yields better performance.






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






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






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






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






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






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






25. A ___________ must not contain a repeating group .






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






27. A ______ attribute can have only one value.






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






29. 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 ____.






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






31. An ERM is not dependent on the ____________.






32. Another word for existence-independent is ____.






33. 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.






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






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






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






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






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






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






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






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






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






43. 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.






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






45. 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.






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






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






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






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






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