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






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






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






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






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






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






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






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






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






10. ____ yields better performance.






11. 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.






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






13. 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.






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






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






16. Another word for existence-independent is ____.






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






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






19. ________ cannot be further subdivided.






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






21. 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.






22. 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.






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






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






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






26. 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.






27. 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 ____.






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






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






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






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






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






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






34. A ______ attribute can have only one value.






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






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






37. 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.






38. A ___________ must not contain a repeating group .






39. 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.






40. 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 ____.






41. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






48. Data redundancy produces ____.






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






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