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






3. A ___________ must not contain a repeating group .






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






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






6. Another word for existence-independent is ____.






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






8. Data redundancy produces ____.






9. An ERM is not dependent on the ____________.






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






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






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






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






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






15. 1NF - 2NF - and 3NF are _____.






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






17. 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.






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






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






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






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






22. 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.






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






24. 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.






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






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






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






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






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






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






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






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






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






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






35. 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 ____.






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






37. 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.






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






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






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






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






42. ____ yields better performance.






43. 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.






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






45. 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.






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






47. ________ cannot be further subdivided.






48. 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.






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






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