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 ____ relationship exists when three entities are associated.






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






3. 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 ____.






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






5. 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.






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






7. An ERM is not dependent on the ____________.






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






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






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






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






12. 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.






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






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






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






16. 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.






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






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






19. ____ yields better performance.






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






21. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






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






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






29. 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 ____.






30. Data redundancy produces ____.






31. 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.






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






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






34. A ___________ must not contain a repeating group .






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






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






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






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






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






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






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






42. Improving ___ leads to more flexible queries.






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






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






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






46. Complex ____ requirements may dictate data transformations - and they may expand the number of entities and attributes withing the design.






47. A ______ attribute can have only one value.






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






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






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