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






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






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






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






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






6. A ______ attribute can have only one value.






7. An ERM is not dependent on the ____________.






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






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






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






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






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






13. ____ yields better performance.






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






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






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






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






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






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






21. 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.






22. 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.






23. 1NF - 2NF - and 3NF are _____.






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






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






26. 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 ____.






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






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






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






30. 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.






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






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






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






34. ________ cannot be further subdivided.






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






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






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






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






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






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






41. Another word for existence-independent is ____.






42. 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.






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






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






46. 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 ____.






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






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






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






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