Database System Chapter 2 study
guide questions and answers.
entity - n
Ans✔
a person, place, thing, or concept, or event for which data can be stored
Qs
attribute - n
Ans✔
a characteristics of an entity or object, An attribute has a name and a data type
Qs
relationship - n
Ans✔
an association between entities
Qs
one to many (1:M) relationship - n
Ans✔
associations among two or more entities that are used by data models. In a 1:M
relationship, one entity instance is associated with many instances of the related
entity
Qs
many to many (M:M) - n
Ans✔
association among two or more entities in which one occurrence of an entity is
associated with many occurrences of a related entity and one occurrence of the
related entity is associated with many occurrences of the first entity
, Qs
one to one - n
Ans✔
associations among two or more entities that are used by data models in a 1:!
relationshp, one antity instance is associated with only one instance of the related
entity
Qs
constraint - n
Ans✔
a restriction placed on data, usually expressed in the form of rules (GPA 0.00-4.00)
Qs
business rule - n
Ans✔
a description of a policy procedure, or principle within an organization. For example,
a pilot cannot be on duty for more than 10 hours during a 24 hour period, or a
teacher can teach up to 4 classes
Qs
hierarchical model - n
Ans✔
an earlt databse model whose bsic concepts and characterics formed the basis for
subsequent database deveopment. This model is based on an upside down tree
structure in which each record is called a segement. Each segement has a 1:M
relationship to the segement direcly below it.
Qs
segment - n
Ans✔
In hierarchical data model, the equivalent of a file system's record type
guide questions and answers.
entity - n
Ans✔
a person, place, thing, or concept, or event for which data can be stored
Qs
attribute - n
Ans✔
a characteristics of an entity or object, An attribute has a name and a data type
Qs
relationship - n
Ans✔
an association between entities
Qs
one to many (1:M) relationship - n
Ans✔
associations among two or more entities that are used by data models. In a 1:M
relationship, one entity instance is associated with many instances of the related
entity
Qs
many to many (M:M) - n
Ans✔
association among two or more entities in which one occurrence of an entity is
associated with many occurrences of a related entity and one occurrence of the
related entity is associated with many occurrences of the first entity
, Qs
one to one - n
Ans✔
associations among two or more entities that are used by data models in a 1:!
relationshp, one antity instance is associated with only one instance of the related
entity
Qs
constraint - n
Ans✔
a restriction placed on data, usually expressed in the form of rules (GPA 0.00-4.00)
Qs
business rule - n
Ans✔
a description of a policy procedure, or principle within an organization. For example,
a pilot cannot be on duty for more than 10 hours during a 24 hour period, or a
teacher can teach up to 4 classes
Qs
hierarchical model - n
Ans✔
an earlt databse model whose bsic concepts and characterics formed the basis for
subsequent database deveopment. This model is based on an upside down tree
structure in which each record is called a segement. Each segement has a 1:M
relationship to the segement direcly below it.
Qs
segment - n
Ans✔
In hierarchical data model, the equivalent of a file system's record type
