Final Exam Set

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Which of the following are properties of relations?

1. Each attribute has a unique name 2.No two rows in a relation are identical 3.There are no multivalued attributes in a relation

A factor to consider when choosing a file organization is

1. Fast data retrieval 2. security 3. efficient storage

Main goals of Normalization

1. minimize data redundancy 2. simplify the enforcement of referential integrity 3.make it easier to maintain data

All of the following are common denormalization opportunities EXCEPT

A one-to-many relationship

What does the following SQL command do? insert into Customer_T values (001,'John Smith','231 West St','Boston','MA','02115');

Adds a new record to the Customer_T table

The SQL command ________ adds one or more new columns to a table.

Alter Table

Alters the Customer_T table, and adds a field called "Type"What does the following SQL statement do? Alter Table Customer_T Add (Type Varchar (2));

Alters the Customer_T table, and adds a field called "Type"

All of the following are valid datatypes in Oracle 11g EXCEPT

Boolean

What does the following SQL statement do? Update Product_T Set Unit_Price = 775 Where Product_ID = 7

Changes the unit price of Product 7 to 775

Sensitivity testing involves

Checking to see if missing data will greatly impact results

Which of the following is a technique for optimizing the internal performance of the relational data model?

Clustering Data

The SQL command ________ defines a logical table from one or more tables or views

Create View

________ is a set of commands used to control a database, which includes security

DCL

________ is a set of commands used to update and query a database

DML

Physical database design decisions must be made carefully because of impacts on

Data Accessibility, Response Time & Security

Anomalies do not generally arise out of transitive dependencies

False

The purpose of data modeling is to document business rules about processes

False

The term legacy system refers to a newly installed database management system.

False

Which of the following is an objective of selecting a data type

Improve Data Integrity

A domain definition consists of the following components EXCEPT

Integrity Constraints

The benefits of a standardized relational language include:

The benefits of a standardized relational language include:-application longevity -reduced training costs -cross system communication

Database access frequencies are estimated from

Transaction Volumes

A cascading delete removes all records in other tables associated with the record to be deleted

True

A data model is a graphical system used to capture the nature and relationships among data.

True

A fact is an association between two or more terms

True

A partial functional dependency is a functional dependency in which one or more nonkey attributes are functionally dependent on part (but not all) of the primary key.

True

A person is an example of an entity.

True

A range control limits the set of permissible values that a field may assume

True

A referential integrity constraint is a rule that maintains consistency among the rows of two relations

True

A relational database establishes the relationships between entities by means of a common field.

True

A single occurrence of an entity is called an entity instance.

True

Keeping the zip code with the city and state in a table is a typical form of denormalization

True

Many of the disadvantages of file processing systems can also be limitations of databases

True

One of the roles of a database analyst is to identify and understand rules that govern data

True

When choosing an identifier, choose one that will not change its value often

True

While business rules are not redundant, a business rule can refer to another business rule.

True

Given a table named store with 5 fields: store_id, address, city, state, zipcode, why would the following insert command not work? insert into store values ('234 Park Street')

You must specify the fields to insert if you are only inserting some of the fields

Which of the following is NOT an advantage of database systems?

elimination of data redundancy, ability of associate deleted data, increased security, program/data independence

Customers, cars, and parts are examples of:

entities

Which of the following is an entity that exists independently of other entity types?

strong

The most common types of entities are:

strong entities

A fact is an association between two or more

terms

A simultaneous relationship among the instances of three entity types is called a ________ relationship.

ternary

Which organizational function should set database standards?

the database administrator

Which of the following is NOT an objective that drove the development and evolution of database technology?

the desire to require programmers to write all file handling functionality

All values that appear in a column of a relation must be taken from the same domain

True

One of the most popular RAD methods is:

prototyping

A workgroup database is stored on a central device called a:

server

The value a field will assume unless the user enters an explicit value for an instance of that field is called a(n):

Default Value

The intent of a business rule is to break down business structure

False

When all multivalued attributes have been removed from a relation, it is said to be in

First Normal Form

Distributing the rows of data into separate files is called

Horizontal Partitioning

The first in a series of steps to follow when creating a table is to

Identify each attribute and its characteristics

The three-schema approach includes which of the following schemas?

Internal, conceptual or external

E. F. Codd developed the relational model in the:

1970's for IBM

A well-structured database establishes the entities between relationships in order to derive the desired information.

False

An entity type on which a strong entity is dependent is called a covariant entity.

False

An example of a term would be the following sentence: "A student registers for a course."

False

Indexes are most useful on small, clustered files

False

Most systems developers believe that data modeling is the least important part of the systems development process.

False

Organizational commitment to a database project is not necessary for its success

False

A functional dependency between two or more nonkey attributes is called a

Transitive Dependency

The number of entity types that participate in a relationship is called the:

degree

A centralized knowledge base of all data definitions, data relationships, screen and report formats, and other system components is called a(n):

repository

A knowledge base of information or facts about an enterprise is called a(n):

repository

With the database approach, data descriptions are stored in a central location known as a:

repository

An attribute of an entity that must have a value for each entity instance is a(n):

required attribute

An attribute that must have a value for every entity (or relationship) instance is a(n):

required attribute

A requirement to begin designing physical files and databases is

1. normalized relations 2. definitions of each attribute 3. technology descriptions

A method for handling missing data is to

1. substitute and estimate for the missing data 2. track missing data with special reports 3. perform sensitivity testing

A candidate key must satisfy all of the following conditions

1. the key must uniquely identify the row 2. the key must be nonredundant 3. each nonkey attribute is functionally dependent upon it

________ is a component of the relational data model included to specify business rules to maintain the integrity of data when they are manipulated.

Data Integrity

The relational data model consists of which components?

Data Structure, Data Manipulation & Data Integrity

Deletes all records from customer_t where the state is equal to HIWhat does the following SQL statement do? Delete from Customer_T where state = 'HI';

Deletes all records from customer_t where the state is equal to HI

The attribute on the left-hand side of the arrow in a functional dependency is the

Determinant

Any create command may be reversed by using a ________ command

Drop

An advantage of partitioning is

Efficiency

The ________ states that no primary key attribute may be null

Entity Integrity Rule

A business rule is a statement of how a policy is enforced or conducted.

False

A constraint is a rule in a database system that can be violated by users.

False

A file organization is a named portion of primary memory

False

A key is a data structure used to determine the location of rows in a file that satisfy some condition

False

A relation is in first normal form if it has no more than one multivalued attribute

False

A transversal dependency is a functional dependency between two or more nonkey attributes

False

A user view is how the user sees the data when it is produced.

False

An anomaly is a type of flaw in the database server

False

Business rules are formulated from a collection of business ramblings.

False

Data names do not have to be unique.

False

Data redundancy is used to establish relationships between data but is never used to improve database performance

False

Databases were developed as the first application of computers to data processing

False

Denormalization is the process of transforming relations with variable-length fields into those with fixed-length fields

False

In an E-R diagram, strong entities are represented by double-walled rectangles

False

In the relational data model, associations between tables are defined through the use of primary keys

False

Organizations that utilize the file processing approach spend only 20 percent of development time on maintenance

False

Personal databases are designed to support a small group of individuals working together on a project.

False

Reduced program maintenance is an advantage of file processing systems.

False

Reduced uptime is a disadvantage of partitioning.

False

Repositories are always used in file processing systems.

False

Some examples of attributes are: eye_color, weight, student_id, STUDENT.

False

The data that you are interested in capturing about an entity is called an instance.

False

The entity integrity rule states that a primary key attribute can be null

False

The name used for an entity type should never be the same in other E-R diagrams on which the entity appears

False

Unlike columns, the rows of a relation may not be interchanged and must be stored in one sequence

False

When systems are automatically generated and maintained, quality is diminished

False

When transforming a one-to-one relationship, a new relation is always created

False

When transforming a unary many-to-many relationship to relations, a recursive foreign key is used

False

When transforming a weak entity, one should create one relation with both the attributes of the strong entity and the attributes of the weak entity

False

With the traditional file processing approach, each application shares data files, thus enabling much data sharing.

False

The smallest unit of application data recognized by system software is a

Field

Which of the following is NOT a cost and/or risk of the database approach?

Improved responsiveness

A form of database specification that indicates all the parameters for data storage that are then input to database implementation is

Physical

DDL is typically used during which phases of the development process?

Physical Design

A(n) ________ is a field of data used to locate a related field or record

Pointer

Purpose of the SQL standard

Purpose of the SQL standard-To specify syntax and semantics of SQL data definition and manipulation -To specify minimal and complete standards, which permit different degrees of adoption in products -To define the data structures and basic operations for SQL databases

An integrity control supported by a DBMS is

Range Control

A rule that states that each foreign key value must match a primary key value in the other relation is called the

Referential Integrity Constraint

The traditional methodology used to develop, maintain and replace information systems is called the:

SDLC ( systems development life cycle)

The ________ is the structure that contains descriptions of objects such as tables and views created by users

Schema

A relation that contains no multivalued attributes and has nonkey attributes solely dependent on the primary key but contains transitive dependencies is in which normal form?

Second Normal Form

A business rule is a statement that defines or constrains some aspect of the business.

True

A business rule should be internally consistent.

True

A candidate key is an attribute, or combination of attributes, that uniquely identifies a row in a relation

True

A foreign key is a primary key of a relation that also is a primary key in another relation.

True

A good data definition is always accompanied by diagrams, such as the entity-relationship diagram.

True

A modern database management system automates more of the backup and recovery tasks than a file system.

True

A well-structured relation contains minimal redundancy and allows users to manipulate the relation without errors or inconsistencies.

True

An entity is a person, place, object, event, or concept in the user environment about which the organization wishes to maintain data.

True

An entity type name should always be a singular noun.

True

Clustering allows for adjacent secondary memory locations to contain rows from several tables.

True

Cost and complexity are just two of the disadvantages of database processing

True

Data modeling is about documenting rules and policies of an organization that govern data.

True

Data names should always relate to business characteristics.

True

Data, rather than processes, are the most complex aspects of many modern information systems.

True

Development starts from scratch with the traditional file processing approach because new file formats, descriptions, and file access logic must be designed for each new program.

True

Enforcement of business rules can be automated through the use of software tools that can interpret the rules and enforce them.

True

File processing systems have been replaced by database systems in most critical business applications today.

True

If an identifier is not assigned, the default primary key for an associative relation consists of the two primary key attributes from the other two relations.

True

In an E-R diagram, an associative entity is represented by a rounded rectangle

True

Information is processed data.

True

One reason for improved application development productivity with the database approach is that file design and low-level implementation details do not need to be handled by the application programmer.

True

Redundancy increases the risk of inconsistent data

True

Security is one advantage of partitioning

True

Separation of metadata from application programs that use the data is called data independence.

True

The E-R model is used to construct a conceptual model.

True

The allowable range of values for a given attribute is part of the domain constraint

True

The columns of a relation can be interchanged without changing the meaning or use of the relation

True

The data repository assists database administrators in enforcing standards.

True

The failure to implement a strong database administrative function is the most common source of database failures in organizations.

True

The relationship between a weak entity type and its owner is an identifying relationship.

True

The user interface includes languages, menus, and other facilities by which users interact with various system components

True

Unplanned duplicate data files are the rule rather than the exception in file processing systems.

True

When normalizing, the goal is to decompose relations with anomalies to produce smaller, well-structured relations

True

A user view is:

a view of part or all of the contents of a database specified for specific user activity

The SDLC phase in which the detailed conceptual data model is created is the ________ phase.

analysis

In a file processing environment, descriptions for data and the logic for accessing the data are built into:

application programs

An entity type name should be all of the following EXCEPT:

as short as possible

A property or characteristic of an entity type that is of interest to the organization is called a(n):

attribute

A person's name, birthday, and social security number are all examples of:

attributes

Data that describe the properties of other data are:

attributes

A ________ defines or constrains some aspect of the business.

business rule

An attribute that can be broken down into smaller parts is called a(n) ________ attribute.

composite

A rule that CANNOT be violated by database users is called a:

constraint

The command for creating a database is

create table

Data modeling may be the most important part of the systems development process because:

data characteristics are important in the design of programs and other systems components.

. A graphical system used to capture the nature and relationships among data is called a(n):

data model

. Database development begins with ________, which establishes the range and general contents of organizational databases.

enterprise data modeling

A person, place, object, event, or concept about which the organization wishes to maintain

entity

The logical representation of an organization's data is called a(n):

entity- relationship model

The most common source of database failures in organizations is:

failure to implement strong database administrator functions

3. Program-data dependence is caused by:

file processing

A(n) ________ is the relationship between a weak entity type and its owner.

identifying relationship

Which of the following is NOT a characteristic of a good business rule?

inconsistent

Purpose of creating indexes?

increases speed or row selection, table joining, and row ordering

2. Older systems that often contain data of poor quality are called ________ systems

legacy

1. A database is an organized collection of ________ related data.

logically

Business policies and rules govern all of the following EXCEPT:

managing employees

The entity integrity rule states that

no primary key attribute can be null

The number of entity types that participate in a Unary relationship is:

one

While Oracle has responsibility for managing data inside a tablespace, the tablespace as a whole is managed by the

operating system

All of the following are properties of metadata EXCEPT

processing logic

All of the following are primary purposes of a database management system (DBMS) EXCEPT:

providing an integrated work environment

Which of the following is NOT a good characteristic of a data name?

relates to technical characteristics of the system

Relational databases establish the relationships between entities by means of common fields included in a file called a(n):

relation

________ are established between entities in a well-structured database so that the desired information can be retrieved.

relationships

In an E-R diagram, there are/is ________ business rule(s) for every relationship.

two

A relationship between the instances of a single entity type is called a ________ relationship.

unary

4. Because applications are often developed independently in file processing systems:

unplanned duplicate data files are the rule rather than the exception

All of the following are objectives when selecting a data type EXCEPT

use a lot of storage space

A(n) ________ is often developed by identifying a form or report that a user needs on a regular basis

user review

An entity type whose existence depends on another entity type is called a ________ entity.

weak

Horizontal partitioning makes sense when

when different categories of a table's rows are processed separately

A good data definition will describe all of the characteristics of a data object EXCEPT:

who can delete the data

.Understanding the steps involved in transforming EER diagrams into relations is important because

you must be able to check the output of a CASE tool


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