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






2. ____ yields better performance.






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






4. Improving ___ leads to more flexible queries.






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






6. An ERM is not dependent on the ____________.






7. A ___________ must not contain a repeating group .






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






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






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






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






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






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






14. Another word for existence-independent is ____.






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






16. A ______ attribute can have only one value.






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






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






19. 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.






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






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






22. According to naming conventions described in Chapter 2 - ___ would be the best name for a column representing the charges per hour in a table named JOB.






23. ________ cannot be further subdivided.






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






25. 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.






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






27. 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 ____.






28. 1NF - 2NF - and 3NF are _____.






29. 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.






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






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






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






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






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






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






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






37. 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 ____.






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






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






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






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






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






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






44. 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.






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






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






47. 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.






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






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






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