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






2. 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.






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






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






5. 1NF - 2NF - and 3NF are _____.






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






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






8. 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.






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






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






11. A ___________ must not contain a repeating group .






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






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






14. 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.






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






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






17. A ______ attribute can have only one value.






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






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






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






21. 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.






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






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






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






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






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






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






28. 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.






29. 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.






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






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






32. 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 ____.






33. ________ cannot be further subdivided.






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






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






36. 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.






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






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






39. Data redundancy produces ____.






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






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






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






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






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






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






46. Another word for existence-independent is ____.






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






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






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






50. Improving ___ leads to more flexible queries.