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 two entities are associated.






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






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






4. 1NF - 2NF - and 3NF are _____.






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






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






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






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






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






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






11. 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.






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






13. 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.






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






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






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






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






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






19. A ___________ must not contain a repeating group .






20. Another word for existence-independent is ____.






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






22. Data redundancy produces ____.






23. 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 ____.






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






25. ________ cannot be further subdivided.






26. 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 ____.






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






28. ____ yields better performance.






29. 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.






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






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






46. A ______ attribute can have only one value.






47. 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.






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






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






50. 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.