Descripción: Quiz incluye correccion de las respuestas
Test: Section 2 Quiz Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Section 2 Quiz (Answer all questions in this section) 1. The transformation from an ER diagram to a physical design involves changing terminology. Primary Unique Identifiers in the ER diagram become __________ and relationships become ____________.
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Primary keys, Foreign keys (*) Foreign keys, Primary keys Unique Keys, Primary keys Foreign keys, mandatory business rules Correct 2. In a physical data model, a relationship is represented as a combination of: (Choose Two)
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(Choose all correct answers) Foreign Key (*) Primary Key or Unique Key (*) Check Constraint or Unique Key Column Correct 3. In a physical data model, an attribute is represented as a/an
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Instance Column (*) Foreign Key Row Correct
4. Flat file databases avoids data duplication. True or False?
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True False (*) Correct 5. What does single table refer to? (Choose Two)
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(Choose all correct answers) A type of database storage method where all of the data elements are stored on top of each other. A fully-relational database system like Microsoft's SQL Server or Oracle's database systems. Non-relational systems that typically store each table and index in separate files and often do not support the SQL language. (*) A database where all of the data is stored in one large table. (*) Correct
Test: Section 2 Quiz Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Section 2 Quiz (Answer all questions in this section) 6. Unique Identifier has a NULL value for each instance of the entity for the lifetime of the instance. True or False
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True False (*) Correct 7. What is the purpose of a Unique Identifier?
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Review (1) Points To identify one unique instance of an entity by using one or more attributes and/or relationships. (*) To identify a specific row within a table, using one or more columns and/or foreign keys. Create an entity that is unlike any other entity aside from itself. To uniquely determine a table and columns within that table. Correct 8. Many reasons exist for creating a conceptual model. Choose three appropriate reasons from the options below. (Choose 3)
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(Choose all correct answers) They model functional and informational needs. (*) They capture the implementation details of the physical model. They capture current and future needs. (*) They accurately describe what a physical model will contain. (*) They model the information flow of data. Incorrect. Refer to Section 2 Lesson 3. 9. Data models are drawn to show users the actual Data that their new system will contain; only Data listed on the Diagram can be entered into the Database. True or False?
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True (*) False Correct 10. Which of the following are reasons we create conceptual models?
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It facilitates discussion; a picture is worth a thousand words It forms important ideal system documentation It takes into account government regulations and laws
It forms a sound basis for physical database design All of the above (*) Correct Test: Section 2 Quiz Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer. Section 2 Quiz (Answer all questions in this section) 11. A barred relationship is mapped to a primary-key column on the many side, just like any other M:1 relationship.
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True False (*) Correct 12. One-to-One relationships are transformed into Foreign Keys in the tables created at either end of that relationship. True or False?
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True False (*) Incorrect. Refer to Section 2 Lesson 6. 13. In the relational model, data is organized in two-dimensional tables called ___________.
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Relations (*) Field Row Tuples Correct 14. Each column in a relation is called an entity. True or False?
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Review (1) Points True False (*) Incorrect. Refer to Section 2 Lesson 2. 15. In the relational model, relationships between relations or tables are created by using?