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






2. A ___________ must not contain a repeating group .






3. Improving ___ leads to more flexible queries.






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






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






6. 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.






7. 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.






8. Data redundancy produces ____.






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






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






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






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






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






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






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






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






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






18. 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.






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






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






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






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






23. ____ yields better performance.






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






25. Another word for existence-independent is ____.






26. 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 ____.






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






28. 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.






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






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






31. 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.






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






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






34. 1NF - 2NF - and 3NF are _____.






35. ________ cannot be further subdivided.






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






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






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






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






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






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






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






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






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






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






47. A ______ attribute can have only one value.






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






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






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