Thanks Mark, Shai, I was getting confused by so many possibilities to do the "almost the same thing" ;)
But have figured it out by peeking into BoolenQuery code that decides if "out of order" should be used..., BQ will pick the right TSDC ... I like it, option 1 it is minimum user code. Cheers, eks ----- Original Message ---- > From: Shai Erera <ser...@gmail.com> > To: java-user@lucene.apache.org > Sent: Wednesday, 30 September, 2009 17:12:38 > Subject: Re: TSDC, TopFieldCollector & co > > I agree. If you need sort-by-score, it's better to use the "fast" search > methods. IndexSearcher will create the appropriate TSDC instance for you, > based on the Query that was passed. > > If you need to create multiple Collectors and pass a kind of Multi-Collector > to IndexSearcher, then you should create TSDC according to Mark's example > above. > > Shai > > On Wed, Sep 30, 2009 at 4:57 PM, Mark Miller wrote: > > > If you want relevance sorting (Sort.Score not Sort.Relevance right?), > > I'd think you want to use TopScoreDocCollector, not TopFieldCollector. > > The only reason to use relevance with TopFieldCollector is if you you > > are doing a nth sort with a field sort as well. > > > > You don't really need to worry about things like turning off the max > > score tracking here - its just going to be the first doc on the queue. > > > > You also do want to specify whether or not to collect docs in order if > > you care about performance: > > > > public static TopScoreDocCollector create(int numHits, boolean > > docsScoredInOrder) > > > > ie: > > > > TopScoreDocCollector.create(nDocs, !weight.scoresDocsOutOfOrder()); > > > > Which means you just want option 1. > > > > -- > > - Mark > > > > http://www.lucidimagination.com > > > > > > > > eks dev wrote: > > > Hi All, > > > > > > What is the best way to achieve the following and what are the > > differences, if I say "I do not normalize scores, so I do not need max score > > tracking, I do not care if hits are returned in doc id order, or any other > > order. I need only to get maxDocs *best scoring* documents": > > > > > > OPTION 1: > > > TopDocs top = ixSearcher.search(q, filter, maxDocs); > > > > > > OPTION 2: > > > final TopScoreDocCollector tfc = TopScoreDocCollector.create(maxDocs, > > false); > > > ixSearcher.search(q, filter, tfc); > > > TopDocs top = tfc.topDocs(); > > > > > > > > > OPTION 3: > > > final TopFieldCollector tfc = > > TopFieldCollector.create(Sort.RELEVANCE, maxDocs, > > > false /* fillFields */, > > > true /* trackDocScores */, > > > false /* trackMaxScore */, > > > false /* docsInOrder */); > > > > > > ixSearcher.search(q.weight(ixSearcher),filter, tfc); > > > TopDocs top = tfc.topDocs(); > > > > > > > > > what are the pros and cons? > > > If I read javadoc correctly, > > > - OPTION 1 tracks max score and delivers doc Ids in order (suboptimal > > performance for my case) > > > - OPTION 2 I do not know abut max score tracking, but doc Ids are not > > required to be in order > > > - OPTION 3 looks like exactly what I want, but one performance comment in > > javadoc about Sort.RELEVANCE made me think if that is the fastest way? > > > > > > What would be recommended here, any other options to achieve the fastest > > search with above defined conditions (no max score tracking and doc id order > > irrelevant)? OPTIN2 looks nice, but as said, I am not sure about max score > > tracking? > > > > > > Thanks, > > > eks > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
