Grant Ingersoll – Exploring Lucene and Solr’s TrieRange Capabilities:

"Now, however, thanks to the new org.apache.lucene.search.trie package (currently located in the contrib/queries area of Lucene, but it may move to the Lucene core, see below) and it’s addition to Solr via a FieldType, Lucene and Solr users can take advantage of much faster range searches."