You omitNorms(), did you also omitTf()? when something like https://issues.apache.org/jira/browse/LUCENE-1345 gets commited, you will have a posibility to see some benefits (e.g. by packing single postings lists as Filters). The code there optimises exactly that case as filters contain no Scoring information ...
try: ----- Original Message ---- > From: Nigel <nigelspl...@gmail.com> > To: java-user@lucene.apache.org > Sent: Friday, 26 June, 2009 4:11:53 > Subject: Optimizing unordered queries > > I recently posted some questions about performance problems with large > indexes. One key thing about our situation is that we don't need sorted > results (either by relevance or any other key). I've been looking into our > memory usage and tracing through some code, which in combination with the > recent posts about setTermInfosIndexDivisor got me thinking about the best > way to do a query where the order of results doesn't matter. > > Currently we're (perhaps naively) doing the equivalent of > query.weight(searcher).scorer(reader).score(collector). Obviously there's a > certain amount of unnecessary calculation that results from this if you > don't care about sorting. Are there any general recommendations for > unordered searching? (We already omit norms.) > > (More details: Of particular interest are things that access the TermInfos, > since that's the major source of RAM usage: if a smaller number of TermInfos > were needed then we could perhaps use an aggressive index divisor setting to > save RAM without a performance penalty. For example, I was thinking about a > custom Similarity implementation that skipped the idf calculations, since > those have to hit the TermInfos.) > > Thanks, > Chris --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
