Schema Evolution publication categorizer

Merging of relationships among data is an important activity in schema integration. The latter can arise as integration of user views In logical database design or as the creation of a global schema from existing databases in a distributed or centralized environment. During the “view lntegration" phase of design, separate views of data held by different user groups are integrated into a single conceptual schema for the entire organization. In this paper we use a variant of the entity relationship model to represent schemas or user views and discuss the problem of integrating relationships from different schemas. Using three major criteria for comparing relationships, we develop a hierarchical comparison scheme. Each case represented by the terminal nodes of this hierarchy is discussed separately and rules of integration are developed. The problem is dealt with in a general sense so that the qualitative discussion is applicable to several other semantic data models. After a paper on object class integration at COHPDEC 84, this work constitutes our next step in the research on schema integration.