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






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. 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 ____.






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






5. ________ cannot be further subdivided.






6. 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.






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






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






9. 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.






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






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






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






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






14. 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.






15. 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.






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






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






18. ____ yields better performance.






19. 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.






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






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






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






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






24. 1NF - 2NF - and 3NF are _____.






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






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






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






28. Data redundancy produces ____.






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






30. 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.






31. Improving ___ leads to more flexible queries.






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






33. 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.






34. Another word for existence-independent is ____.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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