Piotr,
The 'unordered' flag allows spans to be overlapping and still be a match.
I believe this is a feature.
It may seem unusual for a term to be 'near' itself, but it may be more
intuitive if you consider spans that are more than one term long.
spanNear(
[spanNear([contents:test, contents:bunga], 0, true),
spanNear([contents:bunga, contents:test], 0, true)],
10, false
)
This is searching for two phrases, as long as they're reasonably 'close'.
It should match your first example document even though the sub-spans
overlap on the term 'bunga'.
Also, Mark Miller wrote a really nice article on span mechanics that may be
helpful: http://searchhub.org/2009/07/18/the-spanquery/
-Greg
On Fri, Jan 10, 2014 at 7:01 PM, Piotr Pęzik <[email protected]> wrote:
> Hi,
>
> could anyone please tell me if the following behavior is expected in
> Lucene 4.5?
>
> Let's assume we have an index with two documents:
>
> 1. contents: "test bunga bunga test"
> 2. contents: "test bunga test"
>
> We run two SpanNearQueries against this index:
>
> 1. spanNear([contents:bunga, contents:bunga], 0, true)
> 2. spanNear([contents:bunga, contents:bunga], 0, false)
>
> For the first query we get 1 hit. The first document in the example above
> gets matched and the second one doesn't. This make sense, because we want a
> the term "bunga" followed by another "bunga" here.
>
> For the second query both documents get matched. Why does the second
> document with a single occurrence of 'bunga' get matched?
>
> A complete example follows.
>
> Thanks in advance!
>
>
>
> Piotr
>
>
> -----------
>
> import org.apache.lucene.analysis.Analyzer;
> import org.apache.lucene.analysis.standard.StandardAnalyzer;
> import org.apache.lucene.document.Document;
> import org.apache.lucene.document.TextField;
> import org.apache.lucene.index.DirectoryReader;
> import org.apache.lucene.index.IndexWriter;
> import org.apache.lucene.index.IndexWriterConfig;
> import org.apache.lucene.index.Term;
> import org.apache.lucene.search.IndexSearcher;
> import org.apache.lucene.search.TopDocs;
> import org.apache.lucene.search.spans.SpanNearQuery;
> import org.apache.lucene.search.spans.SpanQuery;
> import org.apache.lucene.search.spans.SpanTermQuery;
> import org.apache.lucene.store.Directory;
> import org.apache.lucene.store.FSDirectory;
> import org.apache.lucene.store.RAMDirectory;
> import org.apache.lucene.util.Version;
> import java.io.StringReader;
> import static org.junit.Assert.assertEquals;
>
> class SpansBug {
>
> public static void main(String [] args) throws Exception {
>
> Directory dir = new RAMDirectory();
> Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_45);
> IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_45,
> analyzer);
>
> IndexWriter writer = new IndexWriter(dir, iwc);
> String contents = "contents";
> Document doc1 = new Document();
> doc1.add(new TextField(contents, new StringReader("test bunga
> bunga test")));
> Document doc2 = new Document();
> doc2.add(new TextField(contents, new StringReader("test bunga
> test")));
>
> writer.addDocument(doc1);
> writer.addDocument(doc2);
>
> writer.commit();
>
> IndexSearcher searcher = new IndexSearcher(DirectoryReader.
> open(dir));
>
> SpanQuery stq1 = new SpanTermQuery(new Term(contents,"bunga"));
> SpanQuery stq2 = new SpanTermQuery(new Term(contents,"bunga"));
> SpanQuery [] spqa = new SpanQuery[]{stq1,stq2};
>
> SpanNearQuery spanQ1 = new SpanNearQuery(spqa,0, true);
> SpanNearQuery spanQ2 = new SpanNearQuery(spqa,0, false);
>
> System.out.println(spanQ1);
>
> TopDocs tdocs1 = searcher.search(spanQ1,10);
> assertEquals(tdocs1.totalHits ,1);
>
> System.out.println(spanQ2);
>
> TopDocs tdocs2 = searcher.search(spanQ2,10);
> //Why does the following assertion fail?
> assertEquals(tdocs2.totalHits ,1);
>
>
> }
> }
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [email protected]
> For additional commands, e-mail: [email protected]
>
>
