Gentlemen, On Friday 12 January 2007 21:00, Chuck Williams wrote: > > Doug Cutting wrote on 01/12/2007 09:49 AM: > > Marvin Humphrey wrote: > >> Can you show us some code or pseudo-code for a BooleanScorer that > >> would use impact-sorted posting lists? > > > > Another way to interpret this proposal is index-only: the low-level > > indexing APIs should be general enough to permit impact-sorted posting > > lists, and perhaps an impact-sorted posting list index implementation > > could be provided in the core, but the existing search API's might not > > work well or at all with an impact-sorted index. Perhaps they could > > interoperate at a "weighted filter" level. There could be a separate > > search implementation for impact-sorted indexes, and it could provide > > output as a weighted filter, and the document-sorted search > > implementation could accept weighted-filter clauses. Does that make > > sense? It would be a little like span queries: a separate query > > resolving engine that interoperates with the standard engine, but does > > not replace it. > I think this makes perfect sense. Not all applications place an > emphasis on relevance ranking. E.g., in my current application, the > focus is on categorizing and manipulating large complete result sets. > Lucene as it stands is excellent at that. For very large indexes in > domains where users are most interested in the top few hits, e.g. web > search, then impact-sorted posting lists and partial retrieval have > great value. Adding this capability to lucene in a manner that supports > both uses cases seems the way to go. Sufficient flexibility in the > indexing api's and core implementation(s) so that apps can specify > whether or not they want impact sorting, combined with similarly > flexibility in the query engine(s) to provide complete or incremental > partial retrieval, would achieve this. Weighted-filter clauses could > require the impact-sorted index representation.
A weighted filter clause could already be used as a prescored clause in a boolean query. That makes weighted filters a useful addition to the current search methods. Regards, Paul Elschot --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
