Op Thursday 17 April 2008 06:37:18 schreef Michael Stoppelman: > Actually, I screwed up the timing info. I wasn't including the time > for the QueryWrapperFilter#bits(IndexReader) call. Sadly, > it actually takes longer than the original query that had both terms > included. Bummer. I had really convinced myself till the > thought came to me at lunch :).
For a single query, adding a filter off course has a cost. But when the location part can be reused in later queries, give CachingWrapperFilter a try. Regards, Paul Elschot > > -M > > On Wed, Apr 16, 2008 at 6:43 PM, Karl Wettin <[EMAIL PROTECTED]> wrote: > > Michael Stoppelman skrev: > > > > Hi all, > > > > > I've been doing some performance testing and found that using > > > QueryWrapperFilter for a location field > > > restriction I have to do allows my search results to approach > > > 5-10ms. This > > > was surprising. > > > Before the performance was between 50ms-100ms. > > > > > > The queries from before the optimization look like the following: > > > +(+(text:cats) +(loc:1 loc:2 loc:3 ...)) > > > > > > The QueryWrapperFilter does do a search itself. Why would > > > performance be so > > > drastically different when the > > > QueryWrapperFilter needs to do a search? Does lucene just not > > > have the statistics to optimize this query so it > > > can decide which terms to filter by first? > > > > Do you wonder why a QueryWrapperFilter is faster than a Query? Then > > the answer is that the filter uses a bitset to know if a document > > matches a document or not. For each document that match text:cats > > it checks the flag in the bitset for that document number instead > > of seeking in the index to find out if also match loc:1, loc:2 or > > loc:3. > > > > > > karl > > > > ------------------------------------------------------------------- > >-- To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
