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 ______ attribute can have only one value.






3. 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 ____.






4. Another word for existence-independent is ____.






5. Data redundancy produces ____.






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






7. 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.






8. Improving ___ leads to more flexible queries.






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






10. 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 ____.






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






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






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






14. ________ cannot be further subdivided.






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






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






17. 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.






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






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






20. ____ yields better performance.






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






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






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






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






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






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






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






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






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






30. When a nonkey attribute is the determinate of a key attribute the table is in 3NF but not ____.






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






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






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






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






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






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






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






38. 1NF - 2NF - and 3NF are _____.






39. 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.






40. 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.






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






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






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






44. 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.






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






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






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






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






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






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