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






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






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






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






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






6. 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.






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






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






9. 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.






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






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






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






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






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






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






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






17. A ___________ must not contain a repeating group .






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






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






21. 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.






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






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






24. Data redundancy produces ____.






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






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






27. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






35. ____ yields better performance.






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






37. 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 ____.






38. 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.






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






40. 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.






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






42. A ______ attribute can have only one value.






43. 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.






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






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






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






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