Chapter 6 Questions

Which of the following is the type of logical database model that treats data if they were stored in two-dimensional tables? -Open source DBMS -Relational DBMS -Hierarchical DBMS -Two-tiered DBMS

Relational DBMS

Why do relational databases use primary keys and foreign keys? To create a database. To increase the data redundancy. To create logical relationships. To copy information.

To create logical relationships

A DBMS is special software for creating, storing, organizing, and accessing data from a database. -True -False

True

A characteristic describing an entity is called a(n): -attribute -record -key field -table

attribute

The select operation: combines relational tables to provide the user with more information than is otherwise available. creates a subset consisting of columns in a table. identifies the table from which the columns will be selected. creates a subset consisting of all records in the file that meet stated criteria.

creates a subset consisting of all records in the file that meet stated criteria

A DBMS makes the: logical database available for different analytical views. relational database available for different analytical views. physical database available for different logical views. relational database available for different physical views.

physical database available for different logical views

A field identified in a table as holding the unique identifier of the table's records is called the: unique key. primary key. identifying field. foreign key.

primary key

What are the rules that does not allow someone to create an order for a nonexistent supplier? primary key rule one-to-one ordering referential integrity rules entity-relationship rule

referential integrity rules

In a table for customers, the information about a single customer would reside in a single ______. -column -field -row -table

row

In a relational database, the three basic operations used to develop useful sets of data are: -select, identify, and project -who, what, and where -from, select, and join -select, join, and project

select, join, and project