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






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






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






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






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






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






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






8. ____ yields better performance.






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






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






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






12. 1NF - 2NF - and 3NF are _____.






13. 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.






14. A ___________ must not contain a repeating group .






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






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






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






18. Data redundancy produces ____.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






35. 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.






36. 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.






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






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






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






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






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






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






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






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






45. ________ cannot be further subdivided.






46. An ERM is not dependent on the ____________.






47. 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 ____.






48. 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.






49. 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.






50. 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 ____.