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






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






4. A ___________ must not contain a repeating group .






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






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






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






8. An ERM is not dependent on the ____________.






9. 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.






10. ________ cannot be further subdivided.






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






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






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






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






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






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






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






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






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






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






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






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






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






24. 1NF - 2NF - and 3NF are _____.






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






26. 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.






27. ____ yields better performance.






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






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






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






31. 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 ____.






32. 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.






33. 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.






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






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






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






37. 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.






38. The following step occurs first in the process of building an ERD: create a __________ of the organization's description of operations.






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






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






41. 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.






42. 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.






43. A ______ attribute can have only one value.






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






45. Another word for existence-independent is ____.






46. Improving ___ leads to more flexible queries.






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






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






49. Data redundancy produces ____.






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