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






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






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






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






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






6. 1NF - 2NF - and 3NF are _____.






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






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






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






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






11. 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.






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






13. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






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






22. 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.






23. Another word for existence-independent is ____.






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






25. 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.






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






27. 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 ____.






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






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






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






31. 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 ____.






32. An ERM is not dependent on the ____________.






33. 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.






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






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






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






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






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






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






40. 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.






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






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






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






44. Data redundancy produces ____.






45. 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.






46. 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.






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






48. A ___________ must not contain a repeating group .






49. A ______ attribute can have only one value.






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