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






2. ____ yields better performance.






3. A ___________ must not contain a repeating group .






4. Data redundancy produces ____.






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






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






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






8. An ERM is not dependent on the ____________.






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






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






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






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






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






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






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






16. 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.






17. 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.






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






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






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






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






22. 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.






23. Improving ___ leads to more flexible queries.






24. 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 ____.






25. 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.






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






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






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






29. 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 ____.






30. A ______ attribute can have only one value.






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






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






33. 1NF - 2NF - and 3NF are _____.






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






35. ________ cannot be further subdivided.






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






37. Another word for existence-independent is ____.






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






39. 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.






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






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






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






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






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






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






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






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






48. 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.






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






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