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 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.






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






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






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






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






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 ______ attribute can have only one value.






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






9. 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.






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






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






12. Improving ___ leads to more flexible queries.






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






14. Data redundancy produces ____.






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






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






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






18. 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 ____.






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






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






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






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






23. ________ cannot be further subdivided.






24. An ERM is not dependent on the ____________.






25. Another word for existence-independent is ____.






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






27. 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.






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






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






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






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






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






33. A ___________ must not contain a repeating group .






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






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






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






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






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






39. 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.






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






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






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






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






44. 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.






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






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






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






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






49. ____ yields better performance.






50. 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.