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






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






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






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






5. 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.






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






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






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






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






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






11. Another word for existence-independent is ____.






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






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






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






15. 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 ____.






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






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






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






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






20. 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.






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






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






23. 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.






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






25. 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.






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






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






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






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






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






31. A ______ attribute can have only one value.






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






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






34. A ___________ must not contain a repeating group .






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






36. Improving ___ leads to more flexible queries.






37. Data redundancy produces ____.






38. ____ yields better performance.






39. 1NF - 2NF - and 3NF are _____.






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






41. 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 ____.






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






43. An ERM is not dependent on the ____________.






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






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






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






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






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






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






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