Topic: fundamental concepts such as type, attributes, relationships are all the same

topics > computer science > database > Group: database model

data type
relationship information

attribute-value pairs as information
data as a named set of data objects
data record
data types are not needed
entity-relationship database model
existence of database entities
facts as relationships between entities
kinds of relationships between data
knowledge representation
objects as a set of attributes
problem of classifying information
relationship as an object
representing a relationship
uniform data model


Kent and others have noticed that concepts of data records, relationships, sets, entities, components, categories, attributes, instances, types, classification, and properties all appear to be different interpretations of the same thing. Kent sees relationship as the unifying idea, Zdonik uses objects, Smith uses abstract objects, mathematicians often use sets, Thesa uses naming. ( cbb 1/90)
Subtopic: classification up

Quote: understanding notion of classification leads to fundamental issues in math and philosophy [»wegnP10_1986]

Subtopic: information up

Quote: perhaps information for computer scientists is like ether was for physicists in the last century [»dennPJ3_1995]
Quote: the absence of certain entities is a resource, e.g., the absence of printing on a piece of paper [»petrCA10_1979]

Subtopic: facts up

Quote: a data record can implement a simple fact in a remarkable variety of field configurations [»kentW2_1989]
Quote: some of the ways to record that a salesman serves a territory [»kentW2_1989]
Quote: every fact in a database may be represented in many ways; most actual databases employ a sizable variety of these options [»kentW2_1989]
Quote: the variety of data formats for simple facts makes it difficult to interchange data between sites and applications [»kentW2_1989]
Quote: use IS-A to make statements about the world; cleverly named nodes do not work; e.g., 'Indian-Elephant' [»bracRJ10_1983]

Subtopic: categories, attributes, relationship, entity are the same up

Quote: categories and attributes are the same kind of information [»kentW_1978]
Quote: concepts of record, relationship and entity are mixed up [»kentW_1978]
Quote: all users identify database objects in exactly one way, whether abstract, concrete, entities, or relationships [»coddEF_1990]
Quote: use function notation to indicate a property of an object, a result of a procedure, or a relationship between objects [»fregG_1879]
Quote: relationship, entity, component, category, attribute, and instance and different interpretations of the same abstract objects [»smitJM5_1978]
Quote: attributes and relationships are the same kind of information [»kentW_1978]
Quote: the same piece of information can be a category, an attribute, or a relationship; e.g., parents and children [»kentW_1978]
Quote: similar concepts may be expressed differently across schemas; via relations, or attributes, or classes, or functions [»ahmeR12_1991]

Subtopic: entities and relations up

Quote: relational model treats entities and relations the same; unlike earlier models [»coddEF6_1970]
Quote: foreign keys blur the distinction between entities and relations
Quote: one person's entity is another person's relationship while relations represent both in the same way
Quote: one person's entity is another's relationship; e.g., an airline flight [»coddEF_1990]

Subtopic: relations up

Quote: "There is someone whom Raliph believes is a spy" is a triadic relation between Ralph, spyhood, and the someone [»quinWV_1956]
Quote: IS-A links may indicate subset/superset, a kind of, conceptual containment, role value restriction, or a set's characteristic type [»bracRJ10_1983]
Quote: IS-A links between an individual and a generic indicate instantiation, set membership, predication, conceptual containment, and abstraction [»bracRJ10_1983]

Subtopic: attributes up

Quote: a list of attributes may be a description or a specification; a specification may provide a choice; e.g., "the volume is a cubic meter" [»parnDL_1997]
Quote: in database design, the instance hierarchy may depend on an attribute; e.g., inexpensive products may be treated as bulk items [»buneP5_1986]
Quote: a query with no arguments may be implemented by an attribute or a function; otherwise implement with a function [»meyeB9_1990]
Quote: all names are attribute names since variables, procedures, etc. are attributes of the environment [»maclBJ12_1983]
Quote: attributes are intensions of a single free variable; e.g., spyhood is z(z is a spy)
Quote: while relationships typically do not have properties, they may need properties in the future

Subtopic: data type up

Quote: many possible relationships between the properties of a datatype and the values of the datatype
Quote: things may have a datatype but not be data; e.g., an occam X channel that transports X values [»meekB9_1994]
Quote: types, operations, and properties are themselves objects defined by a type [»zdonSB10_1986]
Quote: types, properties, operations, and constraints are objects with the corresponding type [»zdonSB11_1986]
Quote: by treating properties (including is-a) as objects, have a clean and homogenous way of incorporating behavior [»zdonSB11_1986]
Quote: properties are objects which define relations to other objects, e.g., 'works-for' [»zdonSB10_1986]
Quote: Agenda represents fields and values by categories [»kaplSJ7_1990]

Subtopic: different concepts up

Quote: objects and concepts are totally different since proper names and predicates are totally different

Related Topics up

Group: data type   (34 topics, 730 quotes)
Group: information   (46 topics, 1160 quotes)
Group: philosophy   (60 topics, 2323 quotes)
Group: relationship information   (5 topics, 69 quotes)

Topic: attribute-value pairs as information (57 items)
Topic: classification (65 items)
Topic: data as a named set of data objects (22 items)
Topic: data record (57 items)
Topic: data types are not needed (8 items)
Topic: entities (20 items)
Topic: entity-relationship database model (22 items)
Topic: existence of database entities (19 items)
Topic: facts as relationships between entities (22 items)
Topic: kinds of relationships between data (16 items)
Topic: knowledge representation (41 items)
Topic: objects as a set of attributes (39 items)
Topic: problem of classifying information (42 items)
Topic: relationship as an object (6 items)
Topic: representing a relationship (28 items)
Topic: uniform data model
(19 items)

Updated barberCB 1/06
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Thesa is a trademark of C. Bradford Barber.