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






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






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






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






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






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






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






8. Data redundancy produces ____.






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






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






11. A ______ attribute can have only one value.






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






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






14. 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 ____.






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






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






17. 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.






18. Another word for existence-independent is ____.






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






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






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






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






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






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






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






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






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






29. ________ cannot be further subdivided.






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






31. 1NF - 2NF - and 3NF are _____.






32. Improving ___ leads to more flexible queries.






33. 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.






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






35. 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.






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






37. 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.






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






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






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






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






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






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






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






45. 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.






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






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






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






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






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