問題一覧
1
is a shared, integrated computer structure that stores a collection of end and meta data
Database
2
it’s a raw facts of interesting to the end user.
end user
3
about data, through which the end-user data are integrated and managed
meta data
4
It is a collection of programs that manages the database structure and controls access to the data stored
in the database
DBMS
5
was traditionally composed of a collection of file folders, each properly tagged
and kept in a filing cabinet.
file and file systems
6
consists of logically related data stored in a single logical data repository. It
refers to an organization of components that define and regulate the collection, storage, management, and use
of data within a database environment.
database systems
7
Dbase approach permits the DBA to define and enforce standards among
dbase users in a large organization
Potential of enforcing standards
8
A prime selling feature of dbase approach is that developing a new
application - such as retrieval of certain data from the dbase for printing new application - takes very little time.
Reduced application development time
9
t may be necessary to change the structure of a dbase as requirements change
Flexibility
10
DBMS makes the dbase available to all users. As soon as on user’s
update is applied to the dbase, all other users can immediately see this update.
Availability of up-to-date information
11
DBMS approach permits consolidation of data and applications, thus reducing the
amount of wasteful overlap between activities of data-processing personnel in different projects or departments.
Economies of scale
12
It represents data structures and their characteristics, relations, constraints, transformations, and
other constructs with the purpose of supporting a specific problem domain.
Data models
13
The first step in designing a database, Refers to the process of creating specific data model for a
determined problem domain, It is an iterative, progressive process.
Data modelling
14
the basic building blocks of all data models are entities, attributes,
relationships, and constraints.
Data Model Basic Building Blocks
15
is anything (a person, place, thing or an event) about which data are to be collected and stored,
Represents a particular type of object, entities are “distinguishable”, each entity occurrence is unique and
distinct, may be physical objects, such as customers or products, but entities may also be abstractions, such as
flight routes or musical concerts.
Entity
16
is a characteristics of an entity, CUSTOMER entity would be described by attributes such as
customer last name, customer first name, customer phone, customer address, and customer credit limit,
Attributes are the equivalent of fields in file systems.
Attribute
17
describes an association among entities, A relationship exists between customers and agents
that can be described as follows: an agent can serve many customers, and each customer may be served by one
agent
Relationship
18
a customer may generate many invoices, but each invoice is generated by only a
single customer
one to many
19
an employee may learn many job skills, and each job skill may be learned by many
employees
many to many
20
each of its stores be managed by a single employee
one to one
21
is a restriction placed on the data, are important because they help to ensure data
integrity, are normally expressed in the form of rules.
Constraint
22
first proposed by ________ although interest in the relational model came from several directions, the most
significant research may be attributed to three projects
E.F Codd
23
at IBM’s San Jose Research Laboratory in California, was designed to
prove the practicality of the relational mode
Prototype Relational DBMS System R
24
Project at the University of California at Berkely, Involved
the development of a prototype RDBMS
INGRES (Interactive Graphics Retrieval System)
25
Principally for research into such issues as
query processing and optimization, and functional extension
Peter lee Relational Test Vehicle at the IBM UK Scientific Centre
26
data are on which you can perform meaningful arithmetic procedures
Numeric
27
also known as text data or string data, can contain any character or symbol not intended for
mathematical manipulation
Character
28
attributes contain calendar dates stored in a special format
Date
29
can have only a true or false (yes/no) condition
Logical
30
n relational model, are important because they are used to ensure that each row in a table is
uniquely identifiable
Keys
31
An attribute (or combination of attributes) that uniquely identifies each row in a table
Super Key
32
A minimal (irreducible) super key. A super keythat does not contain a subset of attributes that is
itself a super key
Candidate key
33
A candidate key selected to uniquely identify all the other attribute values in any given row. Cannot
contain null entries
Primary key
34
An attribute (or combination of attributes) used strictly for data retrieval purposes
Secondary key
35
An attribute (or combination of attributes) in one table whose values must either match the
primary key in another table or be null
Foreign key
36
The principle of determination is very important because it is used in the definition of a central relational
database concept known as
functional dependence
37
The key’s role is based on a concept known as
determination
38
The data in relational tables are of limited value unless the data can be manipulated
to generate useful information.
Relational set operators
39
combines all rows from two tables, excluding duplicate rows the tables must have the same attribute
characteristic (the columns and domains must be identified)
Union
40
yields only the rows that appear in both tables you cannot use intersect if one of the attributes is
numeric and one is character-based
Intersect
41
yields all rows in one table that are not found in the other table, that is, it subtracts one table
from the other However, note that subtracting the first table from the second table is not the same as
subtracting the second from the first table
Difference
42
yields all possible pairs of rows from two tables –also known as the Cartesian product Therefore, if
one table has six rows and the other table has three rows,
Product
43
also known as RESTRICT, yields values for all rows found in a table that justify a given condition can be
used to list all of the row values, or it can yield only those row values that match a specific criterion yields a
horizontal subset of a table
select
44
yields all values for selected attributes In other words, yields a vertical subset of a table
project
45
allows information to be combined from two or more tables it is the real power behind the relational
database, allowing the use of independent tables linked by common attributes
join
46
operation uses one single-column table as the divisor (“a”) and one 2-column table as the dividend
(“a” and “b”) The tables must have a common column
divide
47
Provides a detailed description of all tables found within the user/designer created database,
Contains all of the attributes names and characteristics for each table in the system
Data dictionary
48
Also contains metadata, Described as a detailed system data dictionary that describes all
objects within the database
System catalog
49
indicates the use of the same attribute name to label different attributes
homonyms
50
opposite of homonyms and indicates the use of different names to describe the same attribute. It
must be avoided
synonyms
51
is the relational modeling ideal. b.relationship of this type should be the norm in any
relational database design
one to many
52
should be rare in any relational database design
one to one
53
a.cannot be implemented as such in the relational model. b.It is not supported directly in
the relational environment
M:N
54
represents the conceptual database as viewed by the end-user•Depicts the database’s main components:
entities, attributes and relationships
ERD
55
refers to a table row as an entity instance or entity occurrence
ERM
56
s a distinct object (a person, place, thing, concept, or event) in the organization that is to be
represented in the database corresponds to a table –not a row –in the relational environment
Entities
57
is a group of objects with the same properties, which are identified by the enterprise as having an
independent existence.
Entity type
58
is a uniquely identifiable object of an entity type.
Entity occurence
59
is a property that describes some aspect of the object that we wish to record, these are
characteristics of entities
Attributes
60
attribute that must have a value. It cannot be NULL or empty
required attribute
61
attribute that does not require a value. It can be NULL or empty
optional attribute
62
set of possible values for a given attribute
domain
63
One or more attributes that uniquely identify each entity instance, Mapped to
primary keys in table, Are underlined in the ERD
identifiers (PK)
64
Composed of only a single attribute, It is a primary key composed of more than one
attribute
composite identifiers
65
attributes are classified as simple or composite, Composite attribute –
attribute that can be further subdivided to yield additional attributes
composite and simple attributes
66
attribute that cannot be divided
simple attribute
67
attribute that can only have a single value
Single-Valued Attributes
68
attributes that have many values. this should not be implemented in RDBMS
Multi-valued Attributes
69
an attribute whose value is calculated (derived) from other attributes
Derived Attributes
70
used to describe the relationship classification
Connectivity
71
expresses the minimum and maximum number of entity occurrences associated with one
occurrence of the related entity.
Cardinality
72
In ERD, is indicated by placing appropriate numbers beside the entities, using format (x,y)
cardinality
73
exists if the PK of the related entity does not contain a PK
component of the parent entity.
Weak (Non-identifying) Relationships
74
when the PK of the related entity contains a PK component of the parent
entity
Strong (Identifying) Relationship
75
An entity type that is not existence-dependent on some other entity type
Strong Entity Type
76
An entity type that is existence-dependent on some other entity type one that meets
Weak Entity Type
77
one entity occurrence does not require a corresponding entity occurrence in a
particular relationship.
Optional participation
78
one entity occurrence requires a corresponding entity occurrence in a particular
relationship
Mandatory participation
79
the number of participating entity types in a relationship
Degree of a Relationship Type
80
association is maintained within a single entity
Unary Relationship
81
exists when two entities are associated
Binary Relationship
82
exists when three entities are associated
Ternary Relationship
83
It is used to provide commands for defining relation schemes, deleting relations, and
creating indices, among others.
Data Definition Language
84
It is a query-based language that is based on relational algebra and
tuple relational calculus. It can be used to insert, delete, and update tuples in a relation.
Interactive Data Manipulation Language
85
The embedded form of the DML is used to incorporate SQL
statements into programs created using other programming languages such as VB or MS Access.
Embedded Data Manipulation Language
86
It contains commands used for defining relational views.
View Definition
87
The DDL of SQL includes commands for specifying access rights to base relations and views.
Authorization
88
The original SQL used in SYSTEM R included a facility used to specify complex integrity constraints.
Integrity
89
These commands used to specify the start and end of transactions. It is used in data locking
and concurrency controls.
Transaction Control
90
Typically, an SQL expression is made up of three clauses: SELECT,FROM, and WHERE
Basic Structure
91
Used to list the attributes needed to be included in the output of the query.
SELECT
92
Used to include the names of the relations that are to be used in the query.
FROM
93
Consists of a predicate that involves the attributes of the relations described in the FROM clause
WHERE
94
It is a diagram that displays the
relationship of entity sets stored in a database.contain different symbols that use rectangles to represent entities,
ovals to define attributes and diamond shapes to represent relationships. In other words, ER diagrams help to
explain the logical structure of databases
ER DIAGRAM
95
proposed ER Diagram in 1971 to create a uniform convention that can be used for relational
databases and networks. He aimed to use an ER model as a conceptual modeling approach.
Peter Chen
96
This Entity Relationship Diagram symbol represents entity types
Rectangles
97
Symbol represent attributes
Ellipses
98
This symbol represents relationship types
Diamonds
99
It links attributes to entity types and entity types with other relationship types
Lines
100
attributes are underlined
Primary key
ART APP
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79問 • 1年前問題一覧
1
is a shared, integrated computer structure that stores a collection of end and meta data
Database
2
it’s a raw facts of interesting to the end user.
end user
3
about data, through which the end-user data are integrated and managed
meta data
4
It is a collection of programs that manages the database structure and controls access to the data stored
in the database
DBMS
5
was traditionally composed of a collection of file folders, each properly tagged
and kept in a filing cabinet.
file and file systems
6
consists of logically related data stored in a single logical data repository. It
refers to an organization of components that define and regulate the collection, storage, management, and use
of data within a database environment.
database systems
7
Dbase approach permits the DBA to define and enforce standards among
dbase users in a large organization
Potential of enforcing standards
8
A prime selling feature of dbase approach is that developing a new
application - such as retrieval of certain data from the dbase for printing new application - takes very little time.
Reduced application development time
9
t may be necessary to change the structure of a dbase as requirements change
Flexibility
10
DBMS makes the dbase available to all users. As soon as on user’s
update is applied to the dbase, all other users can immediately see this update.
Availability of up-to-date information
11
DBMS approach permits consolidation of data and applications, thus reducing the
amount of wasteful overlap between activities of data-processing personnel in different projects or departments.
Economies of scale
12
It represents data structures and their characteristics, relations, constraints, transformations, and
other constructs with the purpose of supporting a specific problem domain.
Data models
13
The first step in designing a database, Refers to the process of creating specific data model for a
determined problem domain, It is an iterative, progressive process.
Data modelling
14
the basic building blocks of all data models are entities, attributes,
relationships, and constraints.
Data Model Basic Building Blocks
15
is anything (a person, place, thing or an event) about which data are to be collected and stored,
Represents a particular type of object, entities are “distinguishable”, each entity occurrence is unique and
distinct, may be physical objects, such as customers or products, but entities may also be abstractions, such as
flight routes or musical concerts.
Entity
16
is a characteristics of an entity, CUSTOMER entity would be described by attributes such as
customer last name, customer first name, customer phone, customer address, and customer credit limit,
Attributes are the equivalent of fields in file systems.
Attribute
17
describes an association among entities, A relationship exists between customers and agents
that can be described as follows: an agent can serve many customers, and each customer may be served by one
agent
Relationship
18
a customer may generate many invoices, but each invoice is generated by only a
single customer
one to many
19
an employee may learn many job skills, and each job skill may be learned by many
employees
many to many
20
each of its stores be managed by a single employee
one to one
21
is a restriction placed on the data, are important because they help to ensure data
integrity, are normally expressed in the form of rules.
Constraint
22
first proposed by ________ although interest in the relational model came from several directions, the most
significant research may be attributed to three projects
E.F Codd
23
at IBM’s San Jose Research Laboratory in California, was designed to
prove the practicality of the relational mode
Prototype Relational DBMS System R
24
Project at the University of California at Berkely, Involved
the development of a prototype RDBMS
INGRES (Interactive Graphics Retrieval System)
25
Principally for research into such issues as
query processing and optimization, and functional extension
Peter lee Relational Test Vehicle at the IBM UK Scientific Centre
26
data are on which you can perform meaningful arithmetic procedures
Numeric
27
also known as text data or string data, can contain any character or symbol not intended for
mathematical manipulation
Character
28
attributes contain calendar dates stored in a special format
Date
29
can have only a true or false (yes/no) condition
Logical
30
n relational model, are important because they are used to ensure that each row in a table is
uniquely identifiable
Keys
31
An attribute (or combination of attributes) that uniquely identifies each row in a table
Super Key
32
A minimal (irreducible) super key. A super keythat does not contain a subset of attributes that is
itself a super key
Candidate key
33
A candidate key selected to uniquely identify all the other attribute values in any given row. Cannot
contain null entries
Primary key
34
An attribute (or combination of attributes) used strictly for data retrieval purposes
Secondary key
35
An attribute (or combination of attributes) in one table whose values must either match the
primary key in another table or be null
Foreign key
36
The principle of determination is very important because it is used in the definition of a central relational
database concept known as
functional dependence
37
The key’s role is based on a concept known as
determination
38
The data in relational tables are of limited value unless the data can be manipulated
to generate useful information.
Relational set operators
39
combines all rows from two tables, excluding duplicate rows the tables must have the same attribute
characteristic (the columns and domains must be identified)
Union
40
yields only the rows that appear in both tables you cannot use intersect if one of the attributes is
numeric and one is character-based
Intersect
41
yields all rows in one table that are not found in the other table, that is, it subtracts one table
from the other However, note that subtracting the first table from the second table is not the same as
subtracting the second from the first table
Difference
42
yields all possible pairs of rows from two tables –also known as the Cartesian product Therefore, if
one table has six rows and the other table has three rows,
Product
43
also known as RESTRICT, yields values for all rows found in a table that justify a given condition can be
used to list all of the row values, or it can yield only those row values that match a specific criterion yields a
horizontal subset of a table
select
44
yields all values for selected attributes In other words, yields a vertical subset of a table
project
45
allows information to be combined from two or more tables it is the real power behind the relational
database, allowing the use of independent tables linked by common attributes
join
46
operation uses one single-column table as the divisor (“a”) and one 2-column table as the dividend
(“a” and “b”) The tables must have a common column
divide
47
Provides a detailed description of all tables found within the user/designer created database,
Contains all of the attributes names and characteristics for each table in the system
Data dictionary
48
Also contains metadata, Described as a detailed system data dictionary that describes all
objects within the database
System catalog
49
indicates the use of the same attribute name to label different attributes
homonyms
50
opposite of homonyms and indicates the use of different names to describe the same attribute. It
must be avoided
synonyms
51
is the relational modeling ideal. b.relationship of this type should be the norm in any
relational database design
one to many
52
should be rare in any relational database design
one to one
53
a.cannot be implemented as such in the relational model. b.It is not supported directly in
the relational environment
M:N
54
represents the conceptual database as viewed by the end-user•Depicts the database’s main components:
entities, attributes and relationships
ERD
55
refers to a table row as an entity instance or entity occurrence
ERM
56
s a distinct object (a person, place, thing, concept, or event) in the organization that is to be
represented in the database corresponds to a table –not a row –in the relational environment
Entities
57
is a group of objects with the same properties, which are identified by the enterprise as having an
independent existence.
Entity type
58
is a uniquely identifiable object of an entity type.
Entity occurence
59
is a property that describes some aspect of the object that we wish to record, these are
characteristics of entities
Attributes
60
attribute that must have a value. It cannot be NULL or empty
required attribute
61
attribute that does not require a value. It can be NULL or empty
optional attribute
62
set of possible values for a given attribute
domain
63
One or more attributes that uniquely identify each entity instance, Mapped to
primary keys in table, Are underlined in the ERD
identifiers (PK)
64
Composed of only a single attribute, It is a primary key composed of more than one
attribute
composite identifiers
65
attributes are classified as simple or composite, Composite attribute –
attribute that can be further subdivided to yield additional attributes
composite and simple attributes
66
attribute that cannot be divided
simple attribute
67
attribute that can only have a single value
Single-Valued Attributes
68
attributes that have many values. this should not be implemented in RDBMS
Multi-valued Attributes
69
an attribute whose value is calculated (derived) from other attributes
Derived Attributes
70
used to describe the relationship classification
Connectivity
71
expresses the minimum and maximum number of entity occurrences associated with one
occurrence of the related entity.
Cardinality
72
In ERD, is indicated by placing appropriate numbers beside the entities, using format (x,y)
cardinality
73
exists if the PK of the related entity does not contain a PK
component of the parent entity.
Weak (Non-identifying) Relationships
74
when the PK of the related entity contains a PK component of the parent
entity
Strong (Identifying) Relationship
75
An entity type that is not existence-dependent on some other entity type
Strong Entity Type
76
An entity type that is existence-dependent on some other entity type one that meets
Weak Entity Type
77
one entity occurrence does not require a corresponding entity occurrence in a
particular relationship.
Optional participation
78
one entity occurrence requires a corresponding entity occurrence in a particular
relationship
Mandatory participation
79
the number of participating entity types in a relationship
Degree of a Relationship Type
80
association is maintained within a single entity
Unary Relationship
81
exists when two entities are associated
Binary Relationship
82
exists when three entities are associated
Ternary Relationship
83
It is used to provide commands for defining relation schemes, deleting relations, and
creating indices, among others.
Data Definition Language
84
It is a query-based language that is based on relational algebra and
tuple relational calculus. It can be used to insert, delete, and update tuples in a relation.
Interactive Data Manipulation Language
85
The embedded form of the DML is used to incorporate SQL
statements into programs created using other programming languages such as VB or MS Access.
Embedded Data Manipulation Language
86
It contains commands used for defining relational views.
View Definition
87
The DDL of SQL includes commands for specifying access rights to base relations and views.
Authorization
88
The original SQL used in SYSTEM R included a facility used to specify complex integrity constraints.
Integrity
89
These commands used to specify the start and end of transactions. It is used in data locking
and concurrency controls.
Transaction Control
90
Typically, an SQL expression is made up of three clauses: SELECT,FROM, and WHERE
Basic Structure
91
Used to list the attributes needed to be included in the output of the query.
SELECT
92
Used to include the names of the relations that are to be used in the query.
FROM
93
Consists of a predicate that involves the attributes of the relations described in the FROM clause
WHERE
94
It is a diagram that displays the
relationship of entity sets stored in a database.contain different symbols that use rectangles to represent entities,
ovals to define attributes and diamond shapes to represent relationships. In other words, ER diagrams help to
explain the logical structure of databases
ER DIAGRAM
95
proposed ER Diagram in 1971 to create a uniform convention that can be used for relational
databases and networks. He aimed to use an ER model as a conceptual modeling approach.
Peter Chen
96
This Entity Relationship Diagram symbol represents entity types
Rectangles
97
Symbol represent attributes
Ellipses
98
This symbol represents relationship types
Diamonds
99
It links attributes to entity types and entity types with other relationship types
Lines
100
attributes are underlined
Primary key