Hi,
I have the following field type definition:
<fieldtype name="text" class="solr.TextField"
autoGeneratePhraseQueries="true">
<analyzer type="index">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.SynonymGraphFilterFactory" synonyms="synonyms.txt"
ignoreCase="false" expand="true"/>
<filter class="solr.StopFilterFactory" words="stopwords.txt"
ignoreCase="false"/>
</analyzer>
</fieldtype>
Where synonyms and stopwords are defined as follows:
synonyms = out of warranty,oow
stopwords = of
Running the following query:
q=my tv went out *of* warranty something *of*
I get wrong results, with the following explain:
title:my title:tv title:went (title:oow *PhraseQuery(title:"out ?
warranty something"))*
That is, the synonyms is correctly detected, I see the graph information
are correctly reported in the positionLength, it seems they are wrongly
interpreted by the QueryParser.
I guess the reason is the "of" removal operated by the StopFilter, which
* removes the "of" term within the phrase (I wouldn't want that)
* creates a "hole" in the span defined by the "oow" term, which has
been marked as a synonym with a positionLength = 3, therefore
including the next available term (something).
I tried to change the StopFilter in order to ignore stopwords that are
marked as SYNONYM or that are part of a previous synonym span, and it
works: it correctly produces the following query:
title:my title:tv title:went *(title:oow PhraseQuery(title:"out of
warranty"))* title:something
So I'd like to ask your opinion about this. Am I missing something? Do
you think it's better to open a JIRA issue? If the solution is a graph
aware stop filter, do you think it's better to change the existing
filter or to subclass it?
Best,
Andrea
