Metarelational

Metarelational refers to a concept in information theory and data modeling that concerns relationships between relational structures themselves, such as schemas, tables, and the relationships among them. It focuses on meta-relations or higher-order relationships that describe how relations relate to one another, rather than the data stored within those relations.

The formal basis draws on higher-order logic and category theory, or on metamodeling concepts used in model-driven engineering; it treats relations as objects that can be connected by meta-relations, enabling reasoning about schema-level properties like coherence, compatibility, and evolution.

In practice, metarelational reasoning is used in database design, schema integration, ontology alignment, and meta-modeling workflows, where models of data and their inter-relationships are analyzed at a higher level to guide mapping, transformation, or evolution. It supports expressing constraints across schemas, such as dependencies between relations, or consistency conditions between different schemas.

Challenges include formalizing semantics of meta-relations across heterogeneous systems, scalability, and tool support. Because it operates at a level above ordinary relational constraints, it often requires specialized formalisms and abstractions.

See also: relational model, meta-model, higher-order logic, meta-modeling, schema integration, knowledge representation.