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






2. ________ cannot be further subdivided.






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






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






5. 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.






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






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






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






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






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






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






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






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






14. 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 ____.






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






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






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






18. 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.






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






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






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






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






23. 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.






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






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






26. 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.






27. 1NF - 2NF - and 3NF are _____.






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






29. A ___________ must not contain a repeating group .






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






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






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






33. 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.






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






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






36. 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.






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






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






39. ____ yields better performance.






40. An ERM is not dependent on the ____________.






41. Another word for existence-independent is ____.






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






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






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






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






46. 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.






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






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






49. A ______ attribute can have only one value.






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