document: Race : finding and ranking compact connected trees for keyword proximity search over xml documents In this paper , we study the problem of keyword proximity search over XML documents and leverage the efficiency and effectiveness . We take the disjunctive semantics among input keywords into consideration and identify meaningful compact connected trees as the answers of keyword proximity queries . We introduce the notions of Compact Lowest Common Ancestor ( CLCA ) and Maximal CLCA ( MCLCA ) and propose Compact Connected Trees ( CCTrees ) and Maximal CCTrees ( MCCTrees ) to efficiently and effectively answer keyword queries . We propose a novel ranking mechanism , RACE , to Rank compAct Connected trEes , by taking into consideration both the structural similarity and the textual similarity . Our extensive experimental study shows that our method achieves both high search efficiency and effectiveness , and outperforms existing approaches significantly .
doc_bio_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O