Thanks for reading through the long question and providing suggestions Shalin :) You are right about the results being correct. The problem is surely caused because of the approach used.
I guess having different type of documents (for movies, for actors, etc.) will help. However with this approach, I will have to pre-compute and index the number of movies associated with each actor as well. I will need to do this for the other fields as well. Do let me know if you any other suggestions/approaches as well. Thanks, karthik c http://cantspellathing.blogspot.com On Mon, Mar 16, 2009 at 12:37 PM, Shalin Shekhar Mangar < shalinman...@gmail.com> wrote: > On Mon, Mar 16, 2009 at 12:11 PM, karthik c <karthik...@gmail.com> wrote: > > > Hi, > > > > We have a requirement to fetch a set of distinct values of a given field > > that match the given query. We also need to fetch the number of items > > associated with each field value. I figured out a way to do this for > > single-valued fields but am not able to get it to work for multi-valued > > fields. > > > > Long Story: > > Say you have an index of movies, I would like to get a unique set of > > directors matching a query (say "john") and also the number of movies > > directed by each of them. For this example lets assume that "director" is > a > > single valued field. > > > > I came up with one approach to implement this: Search for the query > string > > in the director field and then apply faceting on the same field > (director). > > The search will limit the movie results to the ones directed by directors > > matching the query. Further, the faceting will provide a unique set of > > directors and also the count of movies associated with them. The query > will > > look something like this: > > > > > solr/Movie/select/?q=director:(john)&start=0&rows=0&facet=true&facet.field=raw_director > > > > This query works fine for single-valued fields. However it does not work > in > > the case of multi-valued fields, say we perform a similar search on the > > "actors" (mutli-valued) field, the query will look like: > > > > > solr/Movie/select/?q=actors:(john)&start=0&rows=0&facet=true&facet.field=raw_actors > > In this case, the search will again limit the movie results to the ones > in > > which actors matching the query have acted in. However while faceting the > > results on "actors", the facet results will also contain other actors > that > > have acted in the resulting movies. For eg: say we are searching for > > actors:malkovich, this will return all movies in which John Malkovich has > > acted in. When the faceting is applied on these results, the facet > results > > contain John Malkovich with the correct number of movies. But, the facet > > results also contain other actors who have acted with John Malkovich. The > > facet results for the above query look something like this: > > <lst name="facet_fields"> > > <lst name="raw_actors"> > > <int name="John Malkovich">49</int> > > <int name="Catherine Deneuve">4</int> > > <int name="John Cusack">3</int> > > <int name="Angelina Jolie">2</int> > > <int name="Evangeline Lilly">2</int> > > <int name="Glenne Headly">2</int> > > <int name="Jeremy Irons">2</int> > > <int name="Ray Winstone">2</int> > > </lst> > > </lst> > > The other actors in the above results is obviously not what we expect to > > see, since they do match the original query (i.e. malkovich). > > > > Note that a document in your index represents a movie. You are actually > searching for movies and not actors. Looking from that perspective, the > results are correct. > > You may need to re-think your schema. Make a document represent what you > want to search. Perhaps have different types of documents for 'actors', > 'movies' etc. > > -- > Regards, > Shalin Shekhar Mangar. >
