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






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






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






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






5. An ERM is not dependent on the ____________.






6. Another word for existence-independent is ____.






7. A ______ attribute can have only one value.






8. A ___________ must not contain a repeating group .






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






10. 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.






11. 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.






12. ____ yields better performance.






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






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






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






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






17. 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.






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






19. ________ cannot be further subdivided.






20. 1NF - 2NF - and 3NF are _____.






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






22. 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.






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






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






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






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






27. 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 ____.






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






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






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






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






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






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






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






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






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






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






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






39. 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.






40. Improving ___ leads to more flexible queries.






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






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






43. 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.






44. Data redundancy produces ____.






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






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






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






48. 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 ____.






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






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