: is it possible to get all different values for a : <Field> from a <Hits> object and how to do this?
The ording of your question suggests that the Field you are interested in isn't a field which will have a fairly unique value for every doc (ie: not a "title", more likely an "author" or "category" field). Starting with that assumption, then there is fairly efficient way to get the information you want... Assuming the total set of values for the Field you are interested in is small (relative your index size), you can pre-compute a BitSet for each value indicating which docs match that value in the Field (using a TermFilter). Then store those BitSets in a Map (key'ed by field value) Everytime a search is performed, use a HitCollector that generates a BitSet containing the documents in your result; AND that BitSet against (a copy of) each BitSet in your Map. All of the resulting BitSets with a non-zero cardinality represent values in your results. (As an added bonus the cardinality() of each BitSet is the total number of docs in your result that contain that value) Two caveats: 1) Everytime you modify your index, you have to regen the BitSets in your Map. 2) You have to know the set of all values for the field you are interested in. In many cases, this is easy to determine from the source data while building the index. but it's also possible to get it using IndexReader.termDocs(Term). (I'm doing something like this to provide ancilary information about which categories of documents are most common in the users search result, and what the exact number of documents in those categories is) -Hoss --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]