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. 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.






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






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






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






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






6. 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.






7. Improving ___ leads to more flexible queries.






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






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






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






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






12. 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.






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






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






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






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






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






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






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






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






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






23. A ___________ must not contain a repeating group .






24. Another word for existence-independent is ____.






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






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






27. A ______ attribute can have only one value.






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






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






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






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






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






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






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






35. 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 ____.






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






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






38. 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.






39. 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 ____.






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






41. 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.






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






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






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






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






46. Data redundancy produces ____.






47. ____ yields better performance.






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






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






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