Hi all, starting to work on a new project I've found a boost query configured in a Solr requesthandler. I would show you how this boost query because I'm interested to have some suggestions or advice in what are the benefits/drawbacks of this solution which is new to me.
So let's say that every time the request handler is invoked this BQ is executed. This BQ is composed with more sub-function. Before present the BQ, I've to give some context, let's say we have a field taxonomy that contains few terms (unique) describing the document, for example: doc1 - taxonomy: [ "women", "men", "unisex", ... ] doc2 - taxonomy: [ "men", "most_popular", ... ] doc3 - taxonomy: [ "women", "accessories", ... ] [...] Then in the request handler configuration there are many sub functions like these: product(termfreq(taxonomy,accessories),-5.0) product(termfreq(taxonomy,women),2.0) product(termfreq(taxonomy,most_popular),5.0) [...] This lead to the main function that sums the results of all the previous functions and then scale them to a value between 1 to 100: <str name="bq">def(scale(sum(1.0,product(...),product(...),product(...), [...] ),1.0,100.0),0)</str> I see that the result of function scale() want to influence the score of results, the relevance of the query, boosting the documents matching the terms specified in termfreq(). Comparing the sub function product(termfreq(FIELD,TERM),VALUE) with a common FIELD:TERM^VALUE, I see that the former will not be affected by classic (has no TF/IDF) similarity not sure if this can have benefits. But what I don't really understand the value of the scale function, what are the benefits to scale the results of all the products fn in a value between 1 an 100? I'm also a little afraid that the scale function will not have good performance with a big the number of documents. As usual thanks for your time and best regards, Vincenzo -- Vincenzo D'Amore
