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






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






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






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






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






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






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






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






9. 1NF - 2NF - and 3NF are _____.






10. Data redundancy produces ____.






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






12. ________ cannot be further subdivided.






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






14. 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.






15. 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 ____.






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






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






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






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






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






21. 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.






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






23. 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.






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






25. ____ yields better performance.






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






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






28. 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.






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






30. 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.






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






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






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






34. 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.






35. 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.






36. 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 ____.






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






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






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






40. 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.






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






42. Improving ___ leads to more flexible queries.






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






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






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






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






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






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






49. Another word for existence-independent is ____.






50. A ___________ must not contain a repeating group .