• There is a faceted Search, which is to preview the result of the query in many category.
    • like if we search for ‘apple’
      • the result may be classified into two
        • one is apple fruit
        • one is apple company
  • actually, this is a filter.
    • we can classify before index, and store into index
    • and use value to filter them when query

how to build filter value

  • use Document::add_value

how to use filter when query

  • two ways
    • one is use Xapian::MatchDecider, this return a bool value.
      • or we can use Xapian::ValueSetMatchDecider
        • Xapian::ValueSetMatchDecider(slot, inclusive)
          • slot means which slot to filter
          • inclusive means using filter or reduce
        • use Xapian::ValueSetMatchDecider::add_value(string)
          • user can decide one or many set of value
            • when document belong to one of these value
              • make it filter or stay
    • use MatchSpy