Question

I’m trying to search for a partial word using Solr, but I can’t get it to work.

I’m using this in my schema.xml file.

<fieldType name="text" class="solr.TextField" omitNorms="false">
  <analyzer type="index">
      <tokenizer class="solr.NGramTokenizerFactory" minGramSize="3" maxGramSize="15" />
      <filter class="solr.LowerCaseFilterFactory"/>
  </analyzer>
  <analyzer type="query">
      <tokenizer class="solr.StandardTokenizerFactory"/>
       <filter class="solr.StandardFilterFactory"/>
       <filter class="solr.LowerCaseFilterFactory"/>
       <filter class="solr.PorterStemFilterFactory"/>
       <filter class="solr.WordDelimiterFilterFactory" stemEnglishPossessive="1" splitOnNumerics="1" splitOnCaseChange="1" generateWordParts="1" generateNumberParts="1" catenateWords="1" catenateNumbers="1" catenateAll="1" preserveOriginal="1"/>
  </analyzer>
</fieldType>

Searching for die h won’t work, but die hard returns some results.
I’ve reindexed the database after the above configuration was added.

Here is the url and output when searching for die hard. The debugger is turned on.

Here is the url and output when searching for die h. The debugger is turned on.

I’m using Solr 3.3. Here is the rest of the schema.xml file.

Answer 1

The query you’ve shared is searching the “title_text” field, but the schema you posted above defines the “text” field. Assuming this was just an oversight, and the title_text field is defined as in your post, I think a probable issue is that the NGramTokenizer is configured with minGramSize=”3″, and you are expecting to match using a single-character token.

You could try changing minGramSize to 1, but this will inevitably lead to some very inefficient indexes; and I wonder whether you really are keen on having “e” match every movie with an e in the title?