Hello Carlos, well, you must take into account that you are executing up to 8 queries per request instead of one query per request.
I am not totally sure about the details of the implementation of the max-function-query, but I guess it first iterates over the results of the first max-query, afterwards over the results of the second max-query and so on. This is a much higher complexity than in the case of a normal query. I would suggest you to optimize your request. I don't think that this particular function query is matching *all* docs. Instead I think it just matches those docs specified by your inner-query (although I might be wrong about that). What are you trying to achieve by your request? Regards, Em Am 16.02.2012 16:24, schrieb Carlos Gonzalez-Cadenas: > Hello Em: > > The URL is quite large (w/ shards, ...), maybe it's best if I paste the > relevant parts. > > Our "q" parameter is: > > > "q":"_val_:\"product(query_score,max(query($q8),max(query($q7),max(query($q4),query($q3)))))\"", > > The subqueries q8, q7, q4 and q3 are regular queries, for example: > > "q7":"stopword_phrase:colomba~1 AND stopword_phrase:santa AND > wildcard_stopword_phrase:car^0.7 AND stopword_phrase:hoteles OR > (stopword_phrase:las AND stopword_phrase:de)" > > We've executed the subqueries q3-q8 independently and they're very fast, > but when we introduce the function queries as described below, it all goes > 10X slower. > > Let me know if you need anything else. > > Thanks > Carlos > > > Carlos Gonzalez-Cadenas > CEO, ExperienceOn - New generation search > http://www.experienceon.com > > Mobile: +34 652 911 201 > Skype: carlosgonzalezcadenas > LinkedIn: http://www.linkedin.com/in/carlosgonzalezcadenas > > > On Thu, Feb 16, 2012 at 4:02 PM, Em <mailformailingli...@yahoo.de> wrote: > >> Hello carlos, >> >> could you show us how your Solr-call looks like? >> >> Regards, >> Em >> >> Am 16.02.2012 14:34, schrieb Carlos Gonzalez-Cadenas: >>> Hello all: >>> >>> We'd like to score the matching documents using a combination of SOLR's >> IR >>> score with another application-specific score that we store within the >>> documents themselves (i.e. a float field containing the app-specific >>> score). In particular, we'd like to calculate the final score doing some >>> operations with both numbers (i.e product, sqrt, ...) >>> >>> According to what we know, there are two ways to do this in SOLR: >>> >>> A) Sort by function [1]: We've tested an expression like >>> "sort=product(score, query_score)" in the SOLR query, where score is the >>> common SOLR IR score and query_score is our own precalculated score, but >> it >>> seems that SOLR can only do this with stored/indexed fields (and >> obviously >>> "score" is not stored/indexed). >>> >>> B) Function queries: We've used _val_ and function queries like max, sqrt >>> and query, and we've obtained the desired results from a functional point >>> of view. However, our index is quite large (400M documents) and the >>> performance degrades heavily, given that function queries are AFAIK >>> matching all the documents. >>> >>> I have two questions: >>> >>> 1) Apart from the two options I mentioned, is there any other (simple) >> way >>> to achieve this that we're not aware of? >>> >>> 2) If we have to choose the function queries path, would it be very >>> difficult to modify the actual implementation so that it doesn't match >> all >>> the documents, that is, to pass a query so that it only operates over the >>> documents matching the query?. Looking at the FunctionQuery.java source >>> code, there's a comment that says "// instead of matching all docs, we >>> could also embed a query. the score could either ignore the subscore, or >>> boost it", which is giving us some hope that maybe it's possible and even >>> desirable to go in this direction. If you can give us some directions >> about >>> how to go about this, we may be able to do the actual implementation. >>> >>> BTW, we're using Lucene/SOLR trunk. >>> >>> Thanks a lot for your help. >>> Carlos >>> >>> [1]: http://wiki.apache.org/solr/FunctionQuery#Sort_By_Function >>> >> >
