THe OverRelational Manifesto (ORM)

"… the “The Third Manifesto” is formal and logical. However, The
OverRelational Manifesto (ORM) cannot unconditionally accept the claims of the “The Third Manifesto”, because, in our opinion, the premises, which are its basis, are incomplete. Recall that, answering the first question “What concept in the relational world is the counterpart to the concept "object class" in the object world?”, the “The Third Manifesto” considers the two possible versions 1. domain = object class
2. relation = object class
"The Third Manifestо" argues strongly that the first of these
equations is right and the second is wrong (ORM agrees with this) and, further, its arguments are based just on the first version.

Note that ORM does not claim that the propositions of the “The Third Manifesto” are erroneous. However, ORM does not doubt that these two answers (even the right one) to the question in the preceding paragraph are not only answers to the question about the possible relationship between the “object world” and the “relational world.” There is another approach that can be described by none of the answers proposed in the “The Third Manifesto”.

…

ORM assume that the value describing the state of any entity is a set of relations (or, more definitely, relation values), which is a subset of the relational database describing the state of the whole enterprise.

ORM claims that a system that allows to specify explicitly and to manipulate such subsets is the required system that possesses the properties of both object and relational systems. Accordingly, the main requirement of ORM is the following:

The value describing the state of an entity of an enterprise must be represented as a set of relation values.

Any system satisfying the main requirement will be referred to as an R*O-system.

Remark. Therefore, to relate the “object world” and the “relational world”, ORM associates object with a set of relations. Note that the concept of database appearing in RMD is also defined as a set of relation. Essentially, ORM regards the database as a collection of subsets (not necessarily disjoint, even embeddings are possible); by definition, each subset may also be considered the database.

…

The type system necessary for description and manipulation of data, constraints on the data integrity, and a set of operations are described. It is shown that complex structure definition, in which these types are used, can be treated as definition of set of relational variables (R-variables). The common rule for definition and naming of possible R-variables is formulated, which asserts that the definition of complex reference structure, in which path expression
"name1.*.*.nameZ" is correct (where "*" is any, possible empty
sequense of names), can be interpreted as definition of a relation variable named as "name1.*" , in which the scalar attribute named as
"*.nameZ" exists…"

You can find full version (preprint, PDF, 37 pages) on www.TheORM.narod.ru or on http://www.arxiv.org/abs/cs.DB/0602052

Dear ALL. I'm very interesting for your opinion on the ORM. You can leave you messages here, or on www.TheORM.narod.ru, or by e-mail grigoriev-e_at_yandex.ru. Received on Mon Apr 03 2006 - 11:08:02 CEST