That's what I get for reading code quickly that I haven't used. Similarity.idf() calls MultiSearcher.docFreq() to compute the global idf. So since tf's, lengthNorm's and sloppyFreq's are document-local, coord's and queryNorm's are properties of the query and the idf's, and idf's are computed globally when searching multiple indices, I don't know which problem Daniel is referring to by, "you currently cannot search over several indices without getting an incorrect ranking (except these indices were built from splitting one large index)".
Chuck > -----Original Message----- > From: Doug Cutting [mailto:[EMAIL PROTECTED] > Sent: Thursday, October 21, 2004 2:03 PM > To: Lucene Developers List > Subject: Re: Normalized Scoring -- was RE: idf and explain(), was Re: > Search and Scoring > > Chuck Williams wrote: > > However, I'm not sure this analysis is completely correct due to > MultiSearcher.docFreq() which appears to be trying to redefine the tf's > to be the global value across all indices. It wasn't clear to me how > this code is ever reached, e.g. from TermQuery --> SegmentTermDocs. If > the tf's and idf's are in fact computed globally, then the interleaving > should work as it is, thus I'm guessing they are not. > > Idf's are already computed globally across all indexes. Tf's are local > to the document. In short, scores from a MultiSearcher are the same as > when searching an IndexReader with the same documents. > > Doug > > --------------------------------------------------------------------- > 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]
