General wildcard queries

We now study two techniques for handling general wildcard queries. Both techniques share a common strategy: express the given wildcard query $q_w$ as a Boolean query $Q$ on a specially constructed index, such that the answer to $Q$ is a superset of the set of vocabulary terms matching $q_w$. Then, we check each term in the answer to $Q$ against $q_w$, discarding those vocabulary terms that do not match $q_w$. At this point we have the vocabulary terms matching $q_w$ and can resort to the standard inverted index.