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. Data redundancy produces ____.






2. ________ cannot be further subdivided.






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






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






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






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






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






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






9. 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.






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






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






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






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






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






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






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






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






18. 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 ____.






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






20. 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.






21. Improving ___ leads to more flexible queries.






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






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






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






25. 1NF - 2NF - and 3NF are _____.






26. 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.






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






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






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






30. A ___________ must not contain a repeating group .






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






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






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






34. 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.






35. 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.






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






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






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






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






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






41. 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.






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






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






44. A ______ attribute can have only one value.






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






46. An ERM is not dependent on the ____________.






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






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






49. ____ yields better performance.






50. 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.