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






2. Improving ___ leads to more flexible queries.






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






4. ____ yields better performance.






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






6. A ______ attribute can have only one value.






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






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






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






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






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






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






13. 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.






14. 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.






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






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






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






18. A ___________ must not contain a repeating group .






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






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






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






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






23. 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.






24. Another word for existence-independent is ____.






25. 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 ____.






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






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






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






29. 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.






30. ________ cannot be further subdivided.






31. 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.






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






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






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






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






36. 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.






37. 1NF - 2NF - and 3NF are _____.






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






39. An ERM is not dependent on the ____________.






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






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






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






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






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






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






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






47. 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 ____.






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






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






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