Databases: Ch 1 & 2
True
A data model is usually graphical
True
A data warehouse can store data derived from many sources.
Single-user
A desktop database is a database.
False
A disadvantage of the relational database management system (RDBMS) is its inability to hide the complexities of the relational model from the user.
Field
A is a character or group of characters that has a specific meaning.
File
A is a collection of related records.
Record
A is a logically connected set of one or more fields that describes a person, place, or thing.
Multiuser
A workgroup database is a(n) database.
Modle
A(n) 's main function is to help one understand the complexities of the realworld environment.
Enterprise
A(n) database is used by an organization and supports many users across many departments.
Workgroup
A(n) database supports a relatively small number of users (usually fewer than 50) or a specific department within an organization.
Data anomaly
A(n) develops when all required changes in the redundant data are not made successfully.
DBMS (database management system) database management
A(n) is a collection of programs that manages the database structure and controls access to the data stored in the database.
Constraints
A(n) is a restriction placed on the data.
Query
A(n) is a specific request issued to the DBMS for data manipulation.
Ad hoc query
A(n) is a spur-of-the-moment question.
Enity
A(n) is anything about which data are to be collected and stored.
Relationship
A(n) is bidirectional.
Attribute
A(n) is the equivalent of a field in a file system.
Application
A(n) might be written by a programmer or it might be created through a DBMS utility program.
Enity
A(n) represents a particular type of object in the real world.
Good decision making
Accurate, relevant, and timely information is the key to .
Semistructured
An XML database supports the storage and management of XML data.
False
An advantage of database systems is that you needn't perform frequent updates and apply latest patches.
False
An implementation-ready data model needn't necessarily contain enforceable rules to guarantee the integrity of the data.
True
An implementation-ready data model should contain a description of the data structure that will store the end-user data.
False
An operational database is sometimes referred to as an enterprise database
False
Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.
True
Business rules must be rendered in writing.
False
Corporations use only structured data.
False
Data and information are essentially the same thing.
False
Data anomaly is defined as the condition in which all of the data in the database are consistent with the real-world events and conditions.
True
Data constitute the building blocks of information.
The data always yields consistent results
Data is said to be verifiable if:
False
Data is the result of processing raw facts to reveal its meaning.
True
Data processing can be as simple as organizing data to reveal patterns.
Operational databases
Data warehouse contains historical data obtained from the
False
Database designers determine the data and information that yield the required understanding of the entire business.
False
Database programming languages receive all application requests and translate them into the complex operations required to fulfill those requests.
The metadata describe the data characteristics and the set of relationships that links the data found within the database. For example, the metadata component stores information such as the name of each data element, the type of values (numeric, dates, or text) stored on each data element, and whether the data element can be left empty.
Describe what metadata are and what value they provide to the database system.
Proper database design requires the designer to identify precisely the database's expected use. Designing a transactional database emphasizes accurate and consistent data and operational speed. Designing a data warehouse database emphasizes the use of historical and aggregated data. Designing a database to be used in a centralized, single-user environment requires a different approach from that used in the design of a distributed, multiuser database.
Discuss some considerations when designing a database.
True
Each row in the relational table is known as an entity instance or entity occurrence in the ER model.
Raw facts of interest to the end user
End-user data is .
True
Even when a good database blueprint is available, an applications programmer's view of the data should match that of the manager and the end user.
False
Field refers to a collection of related records.
False
In Chen notation, entities and relationships have to be oriented horizontally; not vertically.
False
In an SQL-based relational database, each table is dependent on every other table.
True
In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.
Data
Information is produced by processing
True
M:N relationships are not appropriate in a relational model.
True
Metadata describe the data characteristics and the set of relationships that links the data found within the database.
Semistructured
Most data that can be encountered are best classified as .
False
One advantage of a database system over previous data management approaches is that the database system is considerably less complex.
True
One disadvantage of a database system over previous data management approaches is increased costs.
False
One disadvantage of the DBMS is that it increases the risk of data security
Formatted
Raw data must be properly for storage, processing and presentation.
False
Structural dependence exists when it is possible to make changes in the file structure without affecting the application program's ability to access the data.
many- to -many
Students and classes have a relationship.
False
The DBMS reveals much of the database's internal complexity to the application programs and users
Data dictionary
The DBMS uses the to look up the required data component structures and relationships, thus relieving programmers from having to code such complex relationships in each program.
Collection of files
The database structure in a DBMS is stored as a .
False
The external model is the representation of the database as "seen" by the DBMS.
False
The hierarchical model is software-independent.
True
The network model has structural level dependence.
True
The only way to access the data in a database is through the DBMS.
Its expected use
The organization of data within folders in a manual file system is determined by .
False
The relational model is hardware-dependent and software-independent.
Query result set
The response of the DBMS to a query is the .
True
The same data might be simultaneously structured and unstructured depending
Database system
The term refers to an organization of components that define and regulate the collection, storage, management and use of data within a database environment.
Island of information
The term refers to scattered locations storing the same basic data.
Context
To reveal meaning, information requires .
True
Today, most relational database products can be classified as object/relational.
A brief explanation of the evolution of file system data processing can be helpful in understanding the data access limitations that databases attempt to overcome. Understanding these limitations is relevant to database designers and developers because database technologies do not make these problems magically disappear—database technologies simply make it easier to create solutions that avoid these problems.
What are some reasons for studying file systems?
Having a DBMS between the end user's applications and the database offers some important advantages. First, the DBMS enables the data in the database to be shared among multiple applications or users. Second, the DBMS integrates the many different users' views of the data into a single all encompassing data repository.
What are the advantages of having the DBMS between the end user's applications and the database?
False
When data are entered into a form and saved, they are placed in the underlying
They enhance the user's ability to undserstand the data
Which of the following is true of spreadsheet applications?
Data Redundancy
Which of the following refers to the situation where different versions of the same data are stored at different places because they weren't updated consistently?
True
Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.
Constraints
are normally expressed in the form of rules.
Structured data
are the result of formatting disorganized data in order to facilitate storage, use and generation of information.
Unstructure
data exist in a format that does not lend itself to processing that yields information.
Unstructured
data exist in the format in which they were collected.
Analytical
databases focus primarily on storing data used to generate information required to make tactical or strategic decisions.
Data inconsistency
exists when different and conflicting versions of the same data appear in different places.
Data inconsistency
exists when different versions of the same data appear in different places.
Data independence
exists when it is possible to make changes in the data storage characteristics without affecting an application program's ability to access data.
Data redundancy
exists when the same data are stored unnecessarily at different places.
XML (Extensible Markup Language)
is a special language used to represent and manipulate data elements in a textual format.
Metadata
is data about data through which the end-user data are integrated and managed.
Data integrity
is defined as the condition in which all of the data in the database are consistent with the real-world events and conditions.
Knowledge
is the body of information and facts about a specific subject.
Information
is the result of processing raw data to reveal its meaning.
Information
is the result of revealing the meaning of raw facts.
Metadata
provide a description of the data characteristics and the set of relationships that link the data found within the database.
In-memory databases
refer to a type of database that stores most of its data in RAM rather than in hard disks.
Performance turning
relates to activities that make a database operate more efficiently in terms of storage and access speed.
Performance tuning
relates to the activities that make the database execute transactions more efficiently in terms of storage and access speed.
DBMSs
serve as the intermediary between the user and the database.
