17. The method of claim 13 , wherein the search structures comprises primary nodes corresponding to the keywords, and searching a wildcard query comprises automatically generating search trees at primary nodes, wherein the search trees comprise secondary nodes corresponding to the wildcard search.
17. The method of claim 13 , wherein the search structures comprises primary nodes corresponding to the keywords, and searching a wildcard query comprises automatically generating search trees at primary nodes, wherein the search trees comprise secondary nodes corresponding to the wildcard search. 19. The method of claim 17 , wherein the search trees comprise tertiary nodes corresponding to the wildcard search.