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. 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 ____.






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






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






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






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






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






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






9. 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.






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






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






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






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






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






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






16. ________ cannot be further subdivided.






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






18. 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.






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






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






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






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






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






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






25. A ___________ must not contain a repeating group .






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






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






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






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






30. 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.






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






32. 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.






33. 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 ____.






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






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






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






37. 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.






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






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






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






41. ____ yields better performance.






42. 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.






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






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






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






47. Improving ___ leads to more flexible queries.






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






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






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