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. Another word for existence-independent is ____.






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






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






4. 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 ____.






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






6. A ___________ must not contain a repeating group .






7. ________ cannot be further subdivided.






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






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






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






11. 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.






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






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






14. 1NF - 2NF - and 3NF are _____.






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






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






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






18. An ERM is not dependent on the ____________.






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






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






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






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






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






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






25. 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.






26. Improving ___ leads to more flexible queries.






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






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






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






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






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






32. A ______ attribute can have only one value.






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






34. 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 ____.






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






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






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






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






39. 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.






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






41. 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.






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






43. Data redundancy produces ____.






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






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






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






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






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






49. 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.






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