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. Another word for existence-independent is ____.






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






3. A ___ entity has a primary key that is partially or totally derived from the parent entity in the relationship.






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






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






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






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






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






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






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






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






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






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






14. Data redundancy produces ____.






15. 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.






16. 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.






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






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






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






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






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






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






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






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






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






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






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






28. An ERM is not dependent on the ____________.






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






30. 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 ____.






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






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






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






34. A ___________ must not contain a repeating group .






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






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






37. 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.






38. 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.






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






40. 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.






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






42. ____ yields better performance.






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






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






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






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






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






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






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






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