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






2. Data redundancy produces ____.






3. ____ yields better performance.






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






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






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






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






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. 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.






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






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






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






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






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






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






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






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






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






19. 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.






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






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






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






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






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






26. 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.






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






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






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






30. A ______ attribute can have only one value.






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






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






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






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






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






36. 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.






37. ________ cannot be further subdivided.






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






39. 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 ____.






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






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






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






43. 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.






44. 1NF - 2NF - and 3NF are _____.






45. A ___________ must not contain a repeating group .






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






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






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






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






50. Another word for existence-independent is ____.