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






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






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






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






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. ________ cannot be further subdivided.






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






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






11. 1NF - 2NF - and 3NF are _____.






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






13. Improving ___ leads to more flexible queries.






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






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






16. 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.






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






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






19. A ______ attribute can have only one value.






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






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






22. 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.






23. 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.






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






25. ____ yields better performance.






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






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






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






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






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






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






32. Another word for existence-independent is ____.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






50. A ___________ must not contain a repeating group .