On character-based index schemes for complex wildcard search in peer-to-peer networks

We present a family of character-based index schemes for wildcard search in peer-to-peer networks. The supported query format allows the two wildcard matching operators '?' and '*' to be used arbitrarily. To our knowledge, no distributed solution for this general form of wildcard search has been proposed thus far. Moreover, the schemes can achieve balanced loads, avoid hot-spots and single points of failure, reduce storage and maintenance costs, and offer ranking mechanisms for matching objects. The main focus is on a thorough comparative study on these index schemes from the following perspectives: query expressiveness, encoding effectiveness, load balance, and search performance.