Showing posts with label databases. Show all posts
Showing posts with label databases. Show all posts

Saturday, June 1, 2013

Concepts of Database Design (7e), Ch. 2

Question 1: Based on the Customer table below, which command lists all information from the table concerning customer 282?
CustomerNum CustomerName Street City State Zip
148 Al’s Appliance 28 Greenway Filmore FL 33336
282 Brookings 3827 Devon Grove FL 33321
Correct Answer: SELECT Customer WHERE CustomerNum=282 GIVING Answer

Question 2: A ____ query creates a new table using the query results.
Correct Answer: make-table

Question 3: Each column in a table should have a unique name, and entries in each column should all “match” this column name.
Correct Answer: True

Question 4: An unnormalized relation is a table that has more than one row.
Correct Answer: False

Question 5: If you are sorting records by more than one field, the more important field is called the ____.
Correct Answer: primary sort key

Question 6: The concept of grouping means that statistics will be calculated for individual records.
Correct Answer: False

Question 7: The ____ operator is used to concatenate every row in the first table with every row in the second table.
Correct Answer: product

Question 8: The ____ key of a table is the column or collection of columns that uniquely identifies a given row in that table.
Correct Answer: primary

Question 9: Count, Sum, Avg, Max, and Min are a few of the built-in statistics or ____ functions that can be used in a query.
Correct Answer: aggregate

Question 10: A query is a question represented in a way that the DBMS can recognize and process.
Correct Answer: True

Question 11: Based on the statement below, which of the following is the primary key?
Rep (RepNum, LastName, FirstName, Street, City, State, Zip, Commission, Rate)
Correct Answer: RepNum

Question 12: The compound criteria (conditions) are created by using ____.
Correct Answer: AND, OR

Question 13: A relational database is a collection of relations.
Correct Answer: True

Question 14: Using the product operator, if table A has 4 rows and table B has 4 rows, the number of rows in the product of these two tables is ____.
Correct Answer: 16

Question 15: You can restrict the output from a join to include only certain columns by using the ____ command.
Correct Answer: PROJECT

Question 16: The ____ command within relational algebra includes the word OVER followed by a list of the columns to be included.
Correct Answer: PROJECT

Question 17: A relation is a(n) ____.
Correct Answer: table

Question 18: QBE is a visual approach to writing queries.
Correct Answer: True

Question 19: A query that changes data is a(n) ____ query.
Correct Answer: update

Question 20: A column whose value uniquely identifies a given row in the table is the secondary key.
Correct Answer: False

Question 21: In a relation, the order of the columns is important.
Correct Answer: False

Question 22: Which operation will allow you to extract data from more than one table?
Correct Answer: Join

Question 23: In an AND criterion, the overall criterion is true if either of the individual criteria is true.
Correct Answer: False

Question 24: When duplicate column names exist in a database and you need to indicate the column to which you are referring, ____.
Correct Answer: write both the table name and the column name, separated by a period

Question 25: In a relation, the order of rows is important.
Correct Answer: False

Question 26: The ____ command within relational algebra takes a vertical subset of a table.
Correct Answer: PROJECT

Question 27: Two tables are considered to be ____ compatible if they have the same number of columns and their corresponding columns represent the same type of data.
Correct Answer: union

Question 28: The ____ operator is performed by the SUBTRACT command in relational algebra.
Correct Answer: difference

Question 29: The comparison operators are +, *, %, and /.
Correct Answer: False

Question 30: The product of two tables is also called the ____ product.
Correct Answer: Cartesian

Question 31: Access automatically adds double quotation marks around values in the design grid that are formatted as Text fields when you run the query or move the insertion point to another cell in the design grid.
Correct Answer: True

Question 32: Rows are also called ____.
Correct Answer: tuples

Question 33: The attributes of an entity become the fields or columns in a table.
Correct Answer: True

Question 34: A relational database handles entities, attributes, and relationships by storing each entity in its own table.
Correct Answer: True

Question 35: The comparison operators are also known as relational operators.
Correct Answer: True

Concepts of Database Design (7e), Ch. 1

An entity is also defined as an attribute.
Correct Answer: False

Employees using a database to enter data create the forms for the database.
Correct Answer: False

Sharing data is one advantage of database processing.
Correct Answer: True

Redundancy wastes space because you are storing different types of data in the same place.
Correct Answer: False

____ is the prevention of unauthorized access to the database.
Correct Answer: Security

A good ____ should provide an opportunity for users to incorporate integrity constraints when they design the database.
Correct Answer: DBMS

Each table in a database represents two or more entities.
Correct Answer: False

Popular ____ include Access, Oracle, DB2, MySQL, and SQL Server.
Correct Answer: DBMSs

A database can be password protected to prevent unauthorized users from accessing the data.
Correct Answer: True

____ are screen objects used to maintain, view, and print data from a database.
Correct Answer: Forms

The relationship between different entities (in different tables) is handled by their common columns.
Correct Answer: True

A(n) ____ is also called a field or column in many database systems.
Correct Answer: attribute

There is a greater impact of failure in a nondatabase, file-oriented system.
Correct Answer: False

A database has ____ if the data in it satisfies all established integrity constraints.
Correct Answer: integrity

An integrity constraint is a rule that ____.
Correct Answer: data must follow in the database

A database will not only hold information about multiple types of entities, but also information about the relationships among these multiple entities.
Correct Answer: True

A DBMS lets you assign users to ____.Answer
Correct Answer: groups

During the ____ process, a database expert determines the structure of the required database.
Correct Answer: database design

A visual way to represent a database is with a(n) ____.
Correct Answer: entity-relationship diagram

An attribute is a characteristic or property of an entity.
Correct Answer: True

The ____ of an entity become the columns in the database table.
Correct Answer: attributes

One disadvantage of a database system is ____.
Correct Answer: a larger file size

Redundancy makes changes more time-consuming since you must change the same information in a number of places.
Correct Answer: True

Storing the same data in more than one place is called ____.
Correct Answer: redundancy

An association between entities is known as a(n) ____.
Correct Answer: relationship

A(n) ____ is a person, place, object, event, or idea for which you want to store and process data.
Correct Answer: entity

____ is a property that lets you change the structure of the database without requiring you to change the programs that access the database.
Correct Answer: Data independence

An attribute is known as a row in most databases.
Correct Answer: False

Programs created with Visual Basic, Java, Perl, PHP, or C++ can access the database directly, rather than having to access it through the DBMS.
Correct Answer: False

Software packages, called database management systems, can do the job of manipulating databases for you.
Correct Answer: True

Which of the following statements is correct?
Correct Answer: In a nondatabase, file-oriented environment, data is often partitioned into several disjointed systems with each system having its own collection of files.

An advantage of using the database approach to processing is that it facilitates consistency.
Correct Answer: True

A(n) ____ is the computer counterpart to an ordinary paper file you might keep in a file cabinet or an accounting ledger.
Correct Answer: data file

A(n) ____ frees programmers who write database access programs from having to engage in mundane data manipulation activities, such as adding new data and deleting existing data.
Correct Answer: DBMS

A person who is in charge of a database within an organization is often called the database ____.
Correct Answer: administrator