Virtuoso supports the following free-text options for bif:contains:

  1. OFFBAND

    : See description for this free-text option in this section .

    • Note: it is useful only if data comers via an Linked Data View and the source relational table uses this trick;

  2. SCORE

    : This free-text option is calculated as described in this section :

    SQL>SPARQL
    SELECT ?s1 as ?c1, ?sc, ?rank
    WHERE
      {
        {
          {
            SELECT ?s1, (?sc * 3e-1) as ?sc, ?o1,
              (sql:rnk_scale (<LONG::IRI_RANK> (?s1))) as ?rank
            WHERE
              {
                ?s1 ?s1textp ?o1 .
                ?o1 bif:contains  '"CNET"'  option (score ?sc)  .
              }
            ORDER BY DESC (?sc * 3e-1 + sql:rnk_scale (<LONG::IRI_RANK> (?s1)))
            LIMIT 20
            OFFSET 0
          }
        }
      };
    
    c1                                              sc      rank
    _________________________________________________________________________
    http://www.mixx.com/stories/45003360/justi...   3           5.881291583872891e-14
    http://www.mixx.com/stories/45099313/bing_...   2.7     5.881291583872891e-14
    http://dbpedia.org/resource/CBS_Interactive       1.5     5.881291583872891e-14
    http://dbpedia.org/resource/CBS_Interactive       1.5     5.881291583872891e-14
    
    4 Rows. -- 1 msec.
    
  3. SCORE_LIMIT

    : This free-text option works as it is in plain SQL free-text. See more details :

    SQL> SPARQL
    SELECT ?s ?sc
    WHERE
      {
        ?s ?p ?o .
        ?o bif:contains "tree" OPTION (score ?sc , score_limit 20)
      };
    
    s                                                                      sc
    VARCHAR                                                                INTEGER
    ________________________________________________________________________________
    
    http://www.openlinksw.com/virtrdf-data-formats#default                 24
    http://www.openlinksw.com/virtrdf-data-formats#default                 24
    http://www.openlinksw.com/virtrdf-data-formats#sql-longvarbinary       21
    http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-dt          20
    http://www.openlinksw.com/virtrdf-data-formats#sql-nvarchar-dt         20
    http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-lang        20
    http://www.openlinksw.com/virtrdf-data-formats#sql-nvarchar-lang       20
    
    7 Rows. -- 2 msec.