I've been pestering you all with a series of questions about disassembling and partially rescoring queries. Every helpful response (thanks) has led me to further reading, and this leads to more questions. If I haven't before, I'll apologize now for the high level of ignorance at which I'm starting. This morning I'm wading in the pool of subqueries.
An example from the wiki: q=product(popularity, query({!dismax qf=text v='solr rocks'})) What's the use/net effect of having a Q that amounts to a number? The final number becomes the score, yes? Why doesn't this example have to use _val_? Is there an assumed defType of func? Reading QueryValueSource.java, I'm wondering about the speed of something like this, or, more to the point, something like a calculation on two queries. Does this iteratively run the subquery for each document otherwise under consideration? I see some code that might be an optimization here. I'm also wondering, is there a way to express that I only want to see results that meet some threshold value for a subquery? Does _val_ (or the local param syntax) manufacture a field that appears in returned documents? If so, is its name _val_? In which case, can there be more than one?