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






3. An ERM is not dependent on the ____________.






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






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






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 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 ____.






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






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






10. 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.






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






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






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






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






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






16. 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.






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






18. Data redundancy produces ____.






19. 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.






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






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






22. 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.






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






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






25. Another word for existence-independent is ____.






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






27. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






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






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






35. A ___________ must not contain a repeating group .






36. A ______ attribute can have only one value.






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






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






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






40. Improving ___ leads to more flexible queries.






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






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






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






44. 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.






45. ________ cannot be further subdivided.






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






47. 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.






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






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






50. ____ yields better performance.