Topic: representing a relationship

topics > computer science > information > Group: relationship information

access to data
data structures
data type

attribute-value pairs as information
database record
data as a named set of data objects
fundamental concepts such as type, attributes, relationships are all the same
hypertext links
kinds of relationships between data
knowledge representation
network and hierarchical databases
recursive data structures
relationship as an object
roles of a relationship
types of hypertext links


There are many ways to represent a relationship. It can be 1) a data object whose components are the roles of the relation (a tuple), 2) an attribute-value pair, 3) a reference or pointer, 4) the type of a data object, 5) a derived relationship.

Because of the multiple ways of representing a relationship, a relationship can also be retrieved in many ways: 1) does it exist, 2) get all matching relationship, 3) get a particular relationship. (cbb 1/90)

Subtopic: relation and roles up

Quote: the meaning of an IS-A link depends on understanding its nodes [»bracRJ10_1983]
Quote: facts can connect any number of things, e.g., John bought a certain computer at Sears [»kentW1_1984]
Quote: need to know what a fact connects and why [»kentW1_1984]
Quote: relationship needs name and for each role: names, types, and least/most participation [»kentW1_1984]
Quote: if a fact connects several things of one type, need to know their roles [»kentW1_1984]
Quote: a relationship type (a fact) has a name and a fixed number of things [»kentW1_1984]
Quote: a pseudo-record contains one field for each role in a fact [»kentW1_1984]

Subtopic: join vs. tuple up

Quote: one person's entity is another's relationship; e.g., an airline flight [»coddEF_1990]
Quote: the relational model defines relationships in two ways: by symbol matching in joins and by coexistence in a tuple [»kentW_1978]
Quote: represent relationships within one thing's record or as a separate record [»kentW_1978]
Quote: while relationships typically do not have properties, they may need properties in the future

Subtopic: relation as attribute up

Quote: is the arc between a relationship node and an object node also a relationship? [»kentW_1978]
Quote: use attributes to express relationships; allows navigational access instead of query access with intermediate objects [»borgA1_1985]
Quote: properties are objects which define relations to other objects, e.g., 'works-for' [»zdonSB10_1986]
Quote: with context modeling can access all related objects by an attribute [»borgA1_1985]

Subtopic: sentence as relation up

Quote: a sentence is words placed into a relationship with one another; generate 20 sentences from 5 random words [»fishS5_2005]

Subtopic: relation as set up

QuoteRef: kayAC6_1968 ;;25 can say John 'is son 'of bill and ask ? 'is son 'of Bill (a set) or John .memberOf. son of bill (true/false). John isn't son of bill undoes the relationship

Subtopic: relation as item up

Quote: L* items contain attributes, relations to other items or sets, and tags (e.g., male) [»grayJC_1973, OK]
Quote: Codil items consist of data name, value, and relationship between them, e.g., rela=father
Quote: Codil items may be qualified by other items; e.g., rela=father | name=sam [»reynCF11_1971, OK]
Quote: RM/T has nonentity associations for relations which are not themselves objects; a single n-ary relation without characteristic entities [»coddEF12_1979]
Quote: in RM/T, associative entity types interrelate entities of other types; superordinate role

Subtopic: relation discovery up

Quote: a system should be able to list the relationships for an object or a pair of objects [»kentW_1978]

Subtopic: n-ary relation up

Quote: a relationship can be one-to-one, one-to-many, or many-to-many [»kentW1_1984]
Quote: a relationship direction can map one to one (simple) or one to many (complex) [»kentW_1978]
Quote: LP is 1 if complete else 0. MP is 1 if singular, else n. e.g., 1*n for 'at least one' [»kentW1_1984, OK]
Quote: CLIENT_ADDRESS_EMPLOYER relation is a combination of RESIDES and EMPLOYED relations; the original relationships and roles are lost [»kentW_1978]
Quote: a 3-way relationship is not equivalent to three binary relationships; otherwise generate superfluous non-facts

Related Topics up

Group: access to data   (12 topics, 307 quotes)
Group: data   (140 topics, 3126 quotes)
Group: data structures   (12 topics, 278 quotes)
Group: data type   (34 topics, 730 quotes)

Topic: attribute-value pairs as information (57 items)
Topic: database record (22 items)
Topic: data as a named set of data objects (22 items)
Topic: fundamental concepts such as type, attributes, relationships are all the same (37 items)
Topic: hypertext links (45 items)
Topic: kinds of relationships between data (16 items)
Topic: knowledge representation (41 items)
Topic: network and hierarchical databases (4 items)
Topic: recursive data structures (18 items)
Topic: relationship as an object (6 items)
Topic: roles of a relationship (8 items)
Topic: types of hypertext links
(19 items)

Updated barberCB 12/04
Copyright © 2002-2008 by C. Bradford Barber. All rights reserved.
Thesa is a trademark of C. Bradford Barber.