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. Improving ___ leads to more flexible queries.






2. 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.






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






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






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






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






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






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






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






10. 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.






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






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






13. 1NF - 2NF - and 3NF are _____.






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






15. 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.






16. Another word for existence-independent is ____.






17. 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 ____.






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






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






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






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






22. Data redundancy produces ____.






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






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






25. ____ yields better performance.






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






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






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






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






30. A ___________ must not contain a repeating group .






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






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






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






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






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






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






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






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






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






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






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






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






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






44. 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.






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






46. 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 ____.






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






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






49. 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.






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