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. 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 ____.






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






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






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






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






6. 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.






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






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






9. An ERM is not dependent on the ____________.






10. Data redundancy produces ____.






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






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






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






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






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






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






17. ________ cannot be further subdivided.






18. 1NF - 2NF - and 3NF are _____.






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






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






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






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






23. 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.






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






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






26. 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.






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






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






29. A ___________ must not contain a repeating group .






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






31. 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.






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






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






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






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






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






37. Another word for existence-independent is ____.






38. 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.






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






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






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






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






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






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






45. A ______ attribute can have only one value.






46. 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 ____.






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






48. Improving ___ leads to more flexible queries.






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






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