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. 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.






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






3. ________ cannot be further subdivided.






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






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






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






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






8. 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.






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






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






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






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






13. A ___________ must not contain a repeating group .






14. Data redundancy produces ____.






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






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






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






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






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






20. Another word for existence-independent is ____.






21. A ______ attribute can have only one value.






22. Improving ___ leads to more flexible queries.






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






24. 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.






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






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






27. 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.






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






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






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






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






33. 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.






34. 1NF - 2NF - and 3NF are _____.






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






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






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






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






39. ____ yields better performance.






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






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






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






43. 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.






44. An ERM is not dependent on the ____________.






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






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






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






48. 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 ____.






49. 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 ____.






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