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






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






3. Improving ___ leads to more flexible queries.






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






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






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






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






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






9. 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.






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






11. 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.






12. 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 ____.






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






14. ____ yields better performance.






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






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






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






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






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






20. 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.






21. Data redundancy produces ____.






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






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






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






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






26. A ___________ must not contain a repeating group .






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






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






29. 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.






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






31. A ______ attribute can have only one value.






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






33. 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.






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






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






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






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






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






39. 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.






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






41. ________ cannot be further subdivided.






42. Another word for existence-independent is ____.






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






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






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






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






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






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






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