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






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






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






4. A ___________ must not contain a repeating group .






5. ____ yields better performance.






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






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






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






9. 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 ____.






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






11. 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.






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






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






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






15. 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.






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






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






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






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






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






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






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






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






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






26. 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.






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






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






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






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






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






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






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






34. 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 ____.






35. Improving ___ leads to more flexible queries.






36. 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.






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






38. Another word for existence-independent is ____.






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






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






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






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






43. ________ cannot be further subdivided.






44. 1NF - 2NF - and 3NF are _____.






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






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






47. A ______ attribute can have only one value.






48. An ERM is not dependent on the ____________.






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






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