title: Different behaviour at synonyms migrating from solr 3.6 to 4.0
body: <p>I'm studying the migration from SolR 3.6 to 4.0.</p>
  
  <p>I've developed a tiny system with no more than 2500 documents. Furthermore, I've developed more than 4100 tests to make sure that at every change, there isn't a deterioration in the functioning of the system.</p>
  
  <p>For this migration, I have kept the default settings of Solr 4.0, just adding my own fieldType (I've seen a lot of new settings at schema.xml and solrconfig.xml).</p>
  
  <p>Thus, in a first run without synonyms, the difference between versions 4.0 and 3.6 was just a sentence (a phrase that in 4.0 works better than 3.6) from 4100. However, if I include synonyms, the deviation becomes much more evident, with considerably worse results at 4.0.</p>
  
  <p>My fieldType is as follows:</p>
  
  <pre><code>&lt;fieldType name="text_es_lemma" class="solr.TextField" positionIncrementGap="100"&gt;
    &lt;analyzer type="query"&gt;
      &lt;tokenizer class="solr.StandardTokenizerFactory"/&gt;
      &lt;filter class="solr.LowerCaseFilterFactory"/&gt;
      &lt;filter class="solr.ASCIIFoldingFilterFactory"/&gt;
      &lt;filter class="solr.SynonymFilterFactory" synonyms="synonyms.lnk" ignoreCase="true" expand="false"/&gt;
      &lt;filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.lnk" format="snowball" enablePositionIncrements="true"/&gt;
      &lt;filter class="solr.KeywordMarkerFilterFactory" protected="protwords.txt"/&gt;
      &lt;filter class="myownlibrary.solr.analysis.SpanishLemmaFilterFactory" dictionary="lang/avatar_dictionary/adj_num_ord-lex.src,lang/avatar_dictionary/basic-lex.src" ignoreCase="true"/&gt;
    &lt;/analyzer&gt;
  
    &lt;analyzer type="index"&gt;
      &lt;tokenizer class="solr.StandardTokenizerFactory"/&gt;
      &lt;filter class="solr.LowerCaseFilterFactory"/&gt;
      &lt;filter class="solr.ASCIIFoldingFilterFactory"/&gt;
      &lt;filter class="solr.SynonymFilterFactory" synonyms="synonyms.lnk" ignoreCase="true" expand="true"/&gt;
      &lt;filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.lnk" format="snowball" enablePositionIncrements="true"/&gt;
      &lt;filter class="solr.KeywordMarkerFilterFactory" protected="protwords.txt"/&gt;
      &lt;filter class="myownlibrary.solr.analysis.SpanishLemmaFilterFactory" dictionary="lang/avatar_dictionary/adj_num_ord-lex.src,lang/avatar_dictionary/basic-lex.src" ignoreCase="true"/&gt;
      &lt;filter class="solr.RemoveDuplicatesTokenFilterFactory" /&gt;
    &lt;/analyzer&gt;
  &lt;/fieldType&gt;
  </code></pre>
  
  <p>The file with synonyms is the same at both versions.</p>
  
  <p>Is there any difference between how synonyms are used at 4.0 and 3.6? Do I have to specify them in a different way at 4.0?</p>