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. A ___________ must not contain a repeating group .






2. ________ cannot be further subdivided.






3. 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.






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






5. 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 ____.






6. 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.






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






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






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






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






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






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






13. 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.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






28. 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.






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






30. Improving ___ leads to more flexible queries.






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






32. 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.






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






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






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






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






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






38. Data redundancy produces ____.






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






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






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






42. ____ yields better performance.






43. 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.






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






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






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






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






48. An ERM is not dependent on the ____________.






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






50. 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.