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






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






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






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






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






6. 1NF - 2NF - and 3NF are _____.






7. 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.






8. A ______ attribute can have only one value.






9. 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.






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






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






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






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






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






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






16. 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.






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






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






19. 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.






20. ____ yields better performance.






21. An ERM is not dependent on the ____________.






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






23. 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 ____.






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






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






26. 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.






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






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






29. Data redundancy produces ____.






30. Improving ___ leads to more flexible queries.






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






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






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






34. 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.






35. A ___________ must not contain a repeating group .






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






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






38. 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.






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






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






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






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






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






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






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






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






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






48. ________ cannot be further subdivided.






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






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