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 ERM is not dependent on the ____________.






2. 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.






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






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






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






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






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






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






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






10. 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 ____.






11. 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.






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






13. 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.






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






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






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






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






18. Improving ___ leads to more flexible queries.






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






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






21. 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.






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






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






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






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






26. Another word for existence-independent is ____.






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






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






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






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






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






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






33. ____ yields better performance.






34. 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.






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






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






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






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






39. A ______ attribute can have only one value.






40. 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.






41. ________ cannot be further subdivided.






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






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






44. 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 ____.






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






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






47. A ___________ must not contain a repeating group .






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






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






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