We study the expressiveness and performance of full-text search languages. Our motivation is to provide a formal basis for comparing full-text search languages and to develop a model for full-text search that can be tightly integrated with structured search. We design a model based on the positions of tokens (words) in the input text, and develop a full-text calculus (FTC) and a full-text algebra (FTA) with equivalent expressive power; this suggests a notion of completeness for full-text search languages. We show that existing full-text languages are incomplete and identify a practical subset of the FTC and FTA that is more powerful than existing languages, but which can still be evaluated efficiently.
展开▼
