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






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






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






4. 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.






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






6. ________ cannot be further subdivided.






7. 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.






8. Data redundancy produces ____.






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






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






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






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






13. 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.






14. Another word for existence-independent is ____.






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






16. 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 ____.






17. An ERM is not dependent on the ____________.






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






19. 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.






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






21. 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.






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






23. 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 ____.






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






25. 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.






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






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






28. ____ yields better performance.






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






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






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






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






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






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






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






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






37. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






43. 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.






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






45. Improving ___ leads to more flexible queries.






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






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






48. 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.






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






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