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






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






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






5. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






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






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






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






16. 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.






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






18. 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.






19. 1NF - 2NF - and 3NF are _____.






20. A ______ attribute can have only one value.






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






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






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






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






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






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






27. 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.






28. 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.






29. 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.






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






31. ________ cannot be further subdivided.






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






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






34. Data redundancy produces ____.






35. A ___________ must not contain a repeating group .






36. 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.






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






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






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






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






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






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






43. 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.






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






45. ____ yields better performance.






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






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






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






49. Another word for existence-independent is ____.






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