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






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






3. ____ yields better performance.






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






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






6. 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.






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






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






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






11. 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.






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






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






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






15. 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.






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






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






18. 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.






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






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






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






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






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






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






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






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






27. ________ cannot be further subdivided.






28. 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.






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






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






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






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






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






34. A ______ attribute can have only one value.






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






36. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






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






45. 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 ____.






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






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






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






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






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