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






2. 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.






3. Data redundancy produces ____.






4. 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.






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






6. A ___________ must not contain a repeating group .






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






8. 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 ____.






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






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






11. 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.






12. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






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






20. 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.






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






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






23. 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.






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






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






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






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






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






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






30. 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.






31. 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.






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






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






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






35. ________ cannot be further subdivided.






36. An ERM is not dependent on the ____________.






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






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






39. ____ yields better performance.






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






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






42. 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 ____.






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






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






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






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






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






48. 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.






49. A ______ attribute can have only one value.






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