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






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






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






5. 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 ____.






6. 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.






7. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






14. 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.






15. 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.






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






17. Data redundancy produces ____.






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






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






20. A ______ attribute can have only one value.






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






22. 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 ____.






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






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






25. 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.






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






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






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






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






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






31. ____ yields better performance.






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






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






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






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






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






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






39. An ERM is not dependent on the ____________.






40. 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.






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






42. ________ cannot be further subdivided.






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






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






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






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






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






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






49. 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.






50. 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.