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. 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.






2. 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.






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






4. 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.






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






6. 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.






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 is one that cannot be subdivided.






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






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






11. A ______ attribute can have only one value.






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






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






14. 1NF - 2NF - and 3NF are _____.






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






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






17. 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 ____.






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






19. Data redundancy produces ____.






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






21. Another word for existence-independent is ____.






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






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






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






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






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






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






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






29. Improving ___ leads to more flexible queries.






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






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






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






33. An ERM is not dependent on the ____________.






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






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






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






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






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






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






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






42. A ___________ must not contain a repeating group .






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






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






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






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






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






48. 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 ____.






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






50. ________ cannot be further subdivided.