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






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






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






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






5. 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.






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






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






8. ________ cannot be further subdivided.






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






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






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






12. 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.






13. Another word for existence-independent is ____.






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






15. 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.






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






17. Improving ___ leads to more flexible queries.






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






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






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






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






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






23. ____ yields better performance.






24. Data redundancy produces ____.






25. 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 ____.






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






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






28. 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.






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






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






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






32. 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.






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






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






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






36. 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.






37. 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.






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






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






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






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






42. 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.






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






44. A ___________ must not contain a repeating group .






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






46. 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 ____.






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






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






49. A ______ attribute can have only one value.






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