On Friday 06 October 2006 14:37, Erick Erickson wrote: ... > Fortunately, the PM agrees that it's silly to think about span queries > involving OR or NOT for this app. So I'm left with something like Jo*n AND > sm*th AND jon?es WITHIN 6.
OR works much the same as term expansion for wildcards. > The only approach that's occurred to me is to create a filter on for the > terms, giving me a subset of my docs that have any terms satisfying the > above. For each doc in the filter, get creative with TermPositionVector for > determining whether the document matches. It seems that this would involve > creating a list of all positions in each doc in my filter that match jo*n, > another for sm*th, and another for jon?es and seeing if the distance > (however I define that) between any triple of terms (one from each list) is > less than 6. > My gut feel is that this explodes time-wise based upon the number of terms > that match. In this particular application, we are indexing 20K books. Based > on indexing 4K of them, this amounts to about a 4G index (although I > acutally expect this to be somewhat larger since I haven't indexed all the > fields, just the text so far). I can't imagine that comparing the expanded > terms for, say, 10,000 docs will be fast. I'm putting together an experiment > to test this though. > > But someone could save me a lot of work by telling me that this is solved > already. This is your chance <G>...... It's solved :) here: http://svn.apache.org/viewvc/lucene/java/trunk/contrib/surround/ The surround query language uses only the spans package for WITHIN like queries, no filters. You may not want to use the parser, but all the rest could be handy. > The expanding queries (e.g. PrefixQuery, RegexQuery, WildcardQuery) all blow > up with TooManyClauses, and I've tried upping the MaxClauses field but that > takes forever and *then* blows up. Even with -Xmx set as high as I can. The surround language has its own limitation on the maximum number of terms expanded for wildcards, and it works nicely even for rather high numbers of terms (thousands) for WITHIN like queries, given enough RAM. It shouldn't be too difficult to add NOT queries within WITHIN, there already is a SpanNotQuery in Lucene to map onto. Regards, Paul Elschot --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
