{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ch13 - ch13 True/False Indicate whether the statement is...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
ch13 True/False Indicate whether the statement is true or false. ____ 1. A relation describes the structure, content, and access controls of a physical data store or database. ____ 2. A relational database management system stores data in tables. ____ 3. A primary key is a field or set of fields in one table used to uniquely identify a row of another table. ____ 4. An attribute is one row of a relation or table. ____ 5. Every table in a relational database must have a primary key. ____ 6. Every table in a relational database must have a foreign key. ____ 7. A foreign key is a field or set of fields stored in one table that also exists as a primary key in another table. ____ 8. Each entity on an entity-relationship diagram (ERD) is represented by one row of a relational database table. ____ 9. A single table in a relational database can represent either an entity or a relationship, but never both. ____ 10. One-to-many and many-to-many relationships are both represented by foreign keys in a relational database. ____ 11. All rows in a table are guaranteed to be unique if the table's primary key is guaranteed to be unique. ____ 12. Referential integrity is a consistent relational database state in which every foreign key value also exists as a primary key value. ____ 13. Referential integrity is normally enforced by the application programmer. ____ 14. A relational database table is in first normal form (1NF) if it has no repeating fields or groups of fields. ____ 15. A relational database table is in third normal form (3NF) if it is in second normal form (2NF) and if every non-key field is functionally dependent on the primary key. ____ 16. A relational database table is in third normal form (3NF) if it is in second normal form (2NF) and if no non- key field is functionally dependent on any other non-key field. ____ 17. Entity-relationship modeling and database normalization are incompatible techniques for relational database design. ____ 18. A transient object must be stored in a file or database between program executions. ____ 19. Object Definition Language (ODL) class definitions derive from the corresponding UML class diagram. ____ 20. Relationships in an object-oriented database are usually represented by embedding a foreign key in each parti- cipating class. ____ 21. The multiplicity of the relationship between Employee and Workstation below is one-to-one. class Employee { attribute string Name attribute integer Salary relationship Workstation Uses inverse Workstation::AssignedTo } class Workstation {
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
attribute string Manufacturer attribute string SerialNumber relationship Employee AssignedTo inverse Employee::Uses } ____ 22. An association class can be created to store the attributes of a many-to-many relationship. ____ 23. A many-to-many relationship is represented differently depending on whether the relationship has any attrib- utes. ____ 24. The object database management system (ODBMS) automatically enforces uniqueness of key attributes in an object database. ____ 25. Key attributes are never declared in an object-oriented database. ____ 26. Just as a child class inherits the data and methods of a parent class, a table representing a child class inherits some or all of its data from the table representing its parent class. ____ 27. The relational database schemas derived from a class diagram and an ERD representing that underlying real- ity are rarely similar. ____ 28. Object-oriented databases have a data type called LONGRAW that provides a way to store binary data. ____ 29. The primary advantage of a single server database architecture is simplicity. ____ 30. A significant disadvantage of a single server database architecture is the potential for performance bottle- necks. Multiple Choice Identify the choice that best completes the statement or answers the question. ____ 31. A(n) ____ describes the structure, content, and access controls of a physical data store or database. a. hybrid database management system c. schema b. relation d. attribute
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}