facetseither

Facetseither is a concept in facet-based data modeling and query languages. It represents a binary operator that expresses a disjunctive choice between two facet expressions, allowing flexible filtering across alternative facet paths.

Semantics and usage: Given a dataset D and two facet expressions F and G over D, facetseither(F, G) denotes the set of items x in D such that x satisfies F or x satisfies G. In most implementations, the operator is realized as a logical OR within the query plan, and results are deduplicated if an item matches both sides.

Examples: In a product catalog with color facets, facetseither(color: red, color: blue) yields items that are red or blue. In a document repository with type facets, facetseither(type: report, type: memo) selects documents that are either reports or memos. The operator can be nested or combined with additional predicates to form more complex filters, such as facetseither(color: red, color: blue) and size: large.

Implementation considerations: Facetseither can impact index design and query planning, since it may require evaluating multiple facet indexes and merging results. Some systems support short-circuit evaluation or prefer distinct result sets to avoid duplicates. Its behavior with respect to precedence and interaction with other facet operators (such as facetand or facetnot) is determined by the specific query language syntax.

See also: facet, disjunction, query language, facetand, facetnot.