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. 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.






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






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






4. Data redundancy produces ____.






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






6. 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.






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






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






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






10. ____ yields better performance.






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






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






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






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






15. 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.






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






17. 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 ____.






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






19. ________ cannot be further subdivided.






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






21. Another word for existence-independent is ____.






22. 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.






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






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






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






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






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






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






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






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






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






33. Improving ___ leads to more flexible queries.






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






35. 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.






36. An ERM is not dependent on the ____________.






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






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






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






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






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






42. 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.






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






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






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






46. 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.






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






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






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






50. A ___________ must not contain a repeating group .