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






2. Improving ___ leads to more flexible queries.






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






4. 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.






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






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






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






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






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






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






11. 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.






12. 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.






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






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






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






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






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






18. ________ cannot be further subdivided.






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






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






21. 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.






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






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






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






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






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






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






28. 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.






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






30. A ___________ must not contain a repeating group .






31. A ______ attribute can have only one value.






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






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






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






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






36. 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.






37. An ERM is not dependent on the ____________.






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






39. 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 ____.






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






41. Data redundancy produces ____.






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






43. 1NF - 2NF - and 3NF are _____.






44. 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.






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






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






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






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






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






50. ____ yields better performance.