On Thu, Oct 15, 2009 at 4:57 AM, Shaun Senecal <ssenecal.w...@gmail.com> wrote:
> Up to Lucene 2.4, this has been working out for us. However, in > Lucene 2.9 this breaks since rewrite() now returns a > ConstantScoreQuery. You can get back to the 2.4 behavior by calling prefixQuery.setRewriteMethod(prefixQuery.SCORING_BOOLEAN_QUERY_REWRITE) before calling rewrite(). > Is there a way I can know that a ConstantScoreQuery will match at > least 1 term (if not, I dont want to add it to the BooleanQuery)? There is a new method in 2.9: MultiTermQuery.getTotalNumberOfTerms(), which returns how many terms were visited during rewrite. Would that work? > My understanding is that Lucene will apply the Filter (C | D) first, > limiting the result set, then apply the Query (A | B). Is this > correct? Actually the filter & query clauses are AND'd in a sort of leapfrog fashion, taking turns skipping up to the other's doc ID and only accepting a doc ID when they both skip to the same point. But this (the mechanics of how Lucene takes a filter into account) is an implementation detail and is likely to change. > If so, the end result is essentially the query: (A | B) & (C | D) Except that C, D contribute no scoring information, if scoring matters. If scoring doesn't matter, entirely (even for A, B), you should use a collector that does not call score() at all to save CPU. Mike --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
