Matching substrings in fulltext search

1. Stop solr.
2. Modify your solr/conf/schema.xml file, the xml block you are looking for starts with something like:

    <fieldType name="text" class="solr.TextField" omitNorms="false">
      <analyzer>
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StandardFilterFactory"/>
        <filter class="solr.LowerCaseFilterFactory"/>
        <filter class="solr.PorterStemFilterFactory"/>
      </analyzer>
    </fieldType>

Change this line/block to:

    <fieldType name="text" class="solr.TextField" omitNorms="false">
      <analyzer>
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StandardFilterFactory"/>
        <filter class="solr.LowerCaseFilterFactory"/>
        <filter class="solr.NGramFilterFactory" minGramSize="2" maxGramSize="15"/>
      </analyzer>

      <analyzer type="query">
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StandardFilterFactory"/>
        <filter class="solr.LowerCaseFilterFactory"/>
      </analyzer>
    </fieldType>

3. (re)Start Solr and run rake sunspot:solr:reindex
4. Things should work