The Associative Model of Data is the first entirely new database architecture since the advent of the Internet, and the first major advance beyond the Relational Model.
The Relational Model of data became commercially dominant in the 1970s. It was briefly challenged in the early 1990s by the Object Model, which failed to cross the chasm into mainstream use and was marginalized when the major relational vendors incorporated object features into their relational products. Since then, whilst the internet has impacted virtually every other significant IT standard, the relational model has remained unchallenged.
The most visible limitation of the relational model has been its inability to handle multimedia files, but the importance of this has been overstated. In fact, the relational model has some far more significant limitations that have not yet been challenged:
- Every new relational application needs a new set of programs developed from scratch, which is labour-intensive, expensive and wasteful.
- Relational applications cannot be readily tailored to the needs of large numbers of individual users, which is an issue for ASPs.
- Relational applications cannot record a piece of information about an individual thing that is not relevant to every other thing of the same type. This limits our ability to continually improve customer service levels.
- Information about identical things in the real world is structured differently
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- in every relational database, so it is difficult and expensive to amalgamate two databases.
It is these limitations, and the first one in particular, that the Associative Model of Data overcomes. Using the Associative Model:
- The same set of programs can be used to implement many different associative applications without being altered or rewritten in any way, allowing users to create new applications from existing ones and offering a substantial saving in software development costs.
- Associative applications can permit features to be used or ignored selectively by individual users without the need for parameterisation or customisation, which is ideally suited to the needs of ASPs.
- An associative database can record information that is relevant only to one thing of a particular type, without demanding that it be relevant to all other things of the same type, allowing us to continue to enhance the quality of customer service.
- Separate associative databases can be readily merged or correlated without extra programming, which saves much of the costs of data warehousing.
Whereas the Relational Model views data as tables, comprising rows of instances and column of attributes, the Associative Model views data as a network of associations expressed through the simple subject-verb-object syntax.
Avis has a credit limit of #10,000
London is located in the UK
A sentence may itself be the source or target of another sentence, so the associative model can manage the most complex schemas:
(Flight BA123 arrives at 16:15) on Saturdays
Avis has an office in (London is located in the UK)
(Mary Peters works for Avis) based at
(Avis has an office in (London is located in the UK))
The power of the Associative Model stems from its ability to store even the most complex schemas in just two data structures:
|
Items |
|
|
Item name |
Surrogate |
|
Mary Peters |
89 |
|
Works for |
56 |
|
Avis |
14 |
|
Based at |
09 |
|
has an office in |
23 |
|
London |
92 |
|
is located in |
35 |
|
the UK |
76 |
|
Associations |
Meaning |
|||
|
Surrogate |
Source |
Verb |
Target |
|
|
134 |
89 |
56 |
14 |
Mary Peters works for Avis |
|
178 |
92 |
35 |
76 |
London is located in the UK |
|
102 |
14 |
23 |
178 |
Avis has an office in (London is located in the UK) |
|
186 |
134 |
09 |
102 |
(Mary Peters works for Avis) based at (Avis has an office in (London is located in the UK)) |
To express the same data structure under the relational model would require eight tables: Person, Company, City, Country, City/Country, Employee, Company/Location, and Employee/Location.
About the Author
Simon Williams is the author of "The Associative Model of Data," which is available via the Lazy Software web site.For More Information
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This was first published in December 2000

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