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






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






3. Data redundancy produces ____.






4. 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 ____.






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






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






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






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






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






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






11. 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.






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






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






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






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






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






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






19. 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.






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






21. 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.






22. An ERM is not dependent on the ____________.






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






24. ____ yields better performance.






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






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






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






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






29. 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.






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






31. Improving ___ leads to more flexible queries.






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






33. A ______ attribute can have only one value.






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






35. 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.






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






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






38. 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.






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






40. Another word for existence-independent is ____.






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






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






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






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






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






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






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






48. 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.






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






50. A ___________ must not contain a repeating group .