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. 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.






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






3. 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.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






18. ____ yields better performance.






19. An ERM is not dependent on the ____________.






20. 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.






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






22. A ___________ must not contain a repeating group .






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






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






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






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






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






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






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






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






31. 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 ____.






32. Data redundancy produces ____.






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






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






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






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






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






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






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






41. Another word for existence-independent is ____.






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






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






44. ________ cannot be further subdivided.






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






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






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






48. Improving ___ leads to more flexible queries.






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






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