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






2. Data redundancy produces ____.






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






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






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






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






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






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






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






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






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






12. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






18. A ______ attribute can have only one value.






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






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






21. ____ yields better performance.






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






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






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






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






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






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






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






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






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






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






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






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






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






35. 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.






36. 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.






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






38. 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.






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






40. An ERM is not dependent on the ____________.






41. Improving ___ leads to more flexible queries.






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






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






44. 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.






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






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






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






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






49. 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.






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