Associative model of data
Encyclopedia
The associative model of data is an alternative data model
for database
systems. Other data models, such as the relational model
and the object data model, are record-based. These models involve encompassing attributes about a thing, such as a car, in a record structure. Such attributes might be registration, colour, make, model, etc. In the associative model, everything which has “discrete independent existence” is modeled as an entity, and relationships between them are modeled as associations. The granularity at which data is represented is similar to schemes presented by Chen (Entity-relationship model
); Bracchi, Paolini and Pelagatti (Binary Relations); and Senko (The Entity Set Model).
A number of claims made about the model by Simon Williams, in his book The Associative Model of Data, distinguish the associative model from more traditional models.
Here's how the associative model would use these two structures to store the piece of information Flight BA1234 arrived at London Heathrow on 12-Dec-05 at 10:25am. There are seven items: the four nouns Flight BA1234, London Heathrow, 12-Dec-05 and 10:25am, and the three verbs arrived at, on and at. We need three links to store the data. They are:
The first link has Flight BA1234 as its source, arrived at as its verb and London Heathrow as its target.
The second link has the first link as its source, on as its verb and the item 12-Dec-05 as its target. (A link that begins with an ellipsis "..." has the previous link as its source.)
The third link has the second link as its source, at as its verb and 10:25am as its target.
Here's an alternative way to write the same thing using parentheses: on 12-Dec-05) at 10:25am
An associative database may be regarded as comprising two tables: one for items and one for links. Each item and each link has an abitrary number (called a surrogate) as an identifier:
Data model
A data model in software engineering is an abstract model, that documents and organizes the business data for communication between team members and is used as a plan for developing applications, specifically how data is stored and accessed....
for database
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
systems. Other data models, such as the relational model
Relational model
The relational model for database management is a database model based on first-order predicate logic, first formulated and proposed in 1969 by Edgar F...
and the object data model, are record-based. These models involve encompassing attributes about a thing, such as a car, in a record structure. Such attributes might be registration, colour, make, model, etc. In the associative model, everything which has “discrete independent existence” is modeled as an entity, and relationships between them are modeled as associations. The granularity at which data is represented is similar to schemes presented by Chen (Entity-relationship model
Entity-relationship model
In software engineering, an entity-relationship model is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements...
); Bracchi, Paolini and Pelagatti (Binary Relations); and Senko (The Entity Set Model).
A number of claims made about the model by Simon Williams, in his book The Associative Model of Data, distinguish the associative model from more traditional models.
Discussion
In an associative database management system, data and metadata (data about data) are stored as two types of things:- Items, each of which has a unique identifier and a name.
- Links, each of which has a unique identifier, together with the unique identifiers of three other things, that represent the source, verb and target of a fact that is recorded about the source in the database. Each of the three things identified by the source, verb and target may each be either a link or an item.
Here's how the associative model would use these two structures to store the piece of information Flight BA1234 arrived at London Heathrow on 12-Dec-05 at 10:25am. There are seven items: the four nouns Flight BA1234, London Heathrow, 12-Dec-05 and 10:25am, and the three verbs arrived at, on and at. We need three links to store the data. They are:
-
- Flight BA1234 arrived at London Heathrow
- ... on 12-Dec-05
- ... at 10:25am
The first link has Flight BA1234 as its source, arrived at as its verb and London Heathrow as its target.
The second link has the first link as its source, on as its verb and the item 12-Dec-05 as its target. (A link that begins with an ellipsis "..." has the previous link as its source.)
The third link has the second link as its source, at as its verb and 10:25am as its target.
Here's an alternative way to write the same thing using parentheses: on 12-Dec-05) at 10:25am
An associative database may be regarded as comprising two tables: one for items and one for links. Each item and each link has an abitrary number (called a surrogate) as an identifier:
| Items | |
| Identifier | Name |
| 77 | Flight BA1234 |
| 08 | London Heathrow |
| 32 | 12-Dec-05 |
| 48 | 10:25am |
| 12 | arrived at |
| 67 | on |
| 09 | at |
| Links | |||
| Identifier | Source | Verb | Target |
| 74 | 77 | 12 | 08 |
| 03 | 74 | 67 | 32 |
| 64 | 03 | 09 | 48 |
See also
- Topic Maps
- Adjacency listAdjacency listIn graph theory, an adjacency list is the representation of all edges or arcs in a graph as a list.If the graph is undirected, every entry is a set of two nodes containing the two ends of the corresponding edge; if it is directed, every entry is a tuple of two nodes, one denoting the source node...
- TriplestoreTriplestoreA triplestore is a purpose-built database for the storage and retrieval of Resource Description Framework metadata.Much like a relational database, one stores information in a triplestore and retrieves it via a query language...
- Attribute-value systemAttribute-value systemAn attribute-value system is a basic knowledge representation framework comprising a table with columns designating "attributes" and rows designating "objects" An attribute-value system is a basic knowledge representation framework comprising a table with columns designating "attributes" (also...
- Vocabulary OneSourceVocabulary OneSourceOneSource is an evolving data analysis tool used internally by the Air Force Command and Control Integration Center's Vocabulary Services Team, and made available to general data management community. It is used by the greater US Department of Defense and NATO community for controlled vocabulary...
External links
- Simon Williams The Associative Model of Data