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What is an Object-Role Model?

A big challenge is posed by the information sharing when it comes to taking commands and controlling the real as well as virtual world enterprises. There are number of formats in which the information is shared and it may or may not have declarative semantics. A partial answer to this problem is provided by the WWW and HTML. Partial because it works only for the information that is either semi – structured or unstructured.

The place is now being taken by the object technology since it represents the structured information that is sh-arable also.

What is Object technology?

– Today, there are many object models available which are later translated in to different representations as per the needs of the project.
The drawback here is the unavailability of the services to serve for all the different types of representation.
– This also insists on the need to have an ability by virtue of which different data models can be inter-operated.
– One of the barriers to information sharing is the inter – language sharing.
– This is so because the systems that have been written in the same language takes up the problem in different will incur some problem during their inter – operation.
– This problem is overcomed by having a common library of objects in the modeling language.
– Few examples of such communities which have adopted this method are OMWG (object modeling working group), OMG domain technical committee, STEP community

Here we talk about another type of model called the object role model which is based up on the ORM technology.

What is Object Role Model?

– Object Role Model technology is used in the field of software engineering and data modeling.
– Graphical symbols are the basic things using which an object role model is built.
– These graphical symbols are known to be based on the first order predicate logic as well as the set theory.
– Using this, the modeler can create an unambiguous definition for an arbitrary universe of discourse.
– In the year of 1970, the term object role model came in to existence but the ORM tools were in use long before the advent of the object role models and were primarily used for the purpose of data modeling.
– The most recent use of the object role models has been in modeling the following:
1. Business rules
2. XML schemas
3. Data ware houses
4. Web forms
5. Requirements engineering and so on.
– Elementary facts lay the foundation for the establishment of an object role model and are expressed with the help of diagrams that in turn are verbalized.
– Those elementary facts are nothing but simple propositions.
– In an object role model, they are represented in an abstract form or we can say fact types.
– For the sample data, the individual propositions are considered.
– A basic difference between a fact and an elementary fact is that during the simplification of an elementary fact, there is always a loss of meaning.
– Therefore, the following is facilitated by this approach driven by the facts:
1. Modeling
2. Transforming
3. Querying information from a domain

– In an object role model, all the elementary facts are treated as relationships and thus can be considered to be free of any attributes.
– Therefore, the idea of grouping the facts as structures is treated as an implementation concern that can be quite disturbing for the semantics.
– The semantic stability is improved by removing the attributes in the object role model and then verbalizing it in to a natural language.
– The fact based modeling makes use of the procedures which map the facts to the structures based up on the attributes just as in the case of the unified modeling language (UML) models or entity relationship (ER) models.

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