On 3/21/08, Chris Hostetter <[EMAIL PROTECTED]> wrote: > > > : I am investigating to implement an aggregate average function for a > document > > : and require help for the same. > > > First off: please don't repost the same email with a different subject > (on either solr list) just because you don't recieve a reply in the first > 24 hours. The Solr community is very healthy and active and willing to > help, but sometimes people get busy and not every question gets addressed > right away (if you check the archives though, typically every question > gets answered eventually -- the few threads that have 0 replies are > usually reposts -- but you have to be a little patient)
sorry for the repost in the dev mailing-list .. I thought i might have to post in the dev list for this kind of question. Second: this sounds exactly like the question you asked a few days ago... > > http://www.nabble.com/sorting-on-aggregate-averages-to16095991.html > > ...did you look into the way the FacetComponent and SimpleFacets work as i > suggested? what you are asking is really much more related to faceting > then to the Function queries (function queries are designed to give you > one value per document) > > Third: something i didn't really catch the first time you asked this > question was how few documents you expected to deal with per request.... > > : The problem is that I have documents containing manufacturer, product, > > : rating (m,p,r) > : and i want to find the top manufacturers for product (p1,p2,...) can be > : around 10 to 20 products > : so i need to compute average rating for each manufacturer for these > : products(p1,p2,..) and sort by this average. > > > If you are only going to query for 10-20 (or even 100) documents, then > you'll have at most 10-20 (or 100) manufactures and ratings. You could > iterate over these and compute the average directly ... this would be a > lot easier and simpler to implement then trying to leverage the faceting > code (or the FunctionQuery code ... like i said it really wasn't designed > for anything like this) Given document schema mpr as : mpr( MID:INT, PID:INT, Rating:float ) with assumptions: Cardinality of M ranges in the order of 10^3 Cardinality of P ranges in the order of 10^2 ... the toltal of records ranging in order of 10^5 the SQL equivalent would be something like: SELECT MID, AVG(Rating) as Average FROM mpr WHERE PID in (p1[,p2,...]) GROUP BY MID ORDER BY Average DESC LIMIT 0, 10; Also I would require to boost the vales based on PIDs (some products have more wight than others effectively computing a wighted average) To handle these queries I am plannig to develop a custom request handler plugin in most generic form to be useful in general. -Hoss > >
