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






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






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






4. Data redundancy produces ____.






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






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






7. 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.






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






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. ____ yields better performance.






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






12. Improving ___ leads to more flexible queries.






13. 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.






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






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






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






17. ________ cannot be further subdivided.






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






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






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






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






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






23. 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.






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






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






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






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






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






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






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






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






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






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






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






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






36. 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 ____.






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






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






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






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






41. 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 ____.






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






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






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






45. 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.






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






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






48. A ______ attribute can have only one value.






49. A ___________ must not contain a repeating group .






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