I've done a lot of recency boosting to documents, and I'm wondering why you would want to do that at index time. If you are continuously indexing new documents, what was "recent" when it was indexed becomes, over time "less recent". Are you unsatisfied with your current performance with the boost function? Query-time recency boosting is a fairly common thing to do, and, if done correctly, shouldn't be a performance concern.
-Jay http://lucidimagination.com On Fri, Jun 4, 2010 at 4:50 PM, Asif Rahman <a...@newscred.com> wrote: > Perhaps I should have been more specific in my initial post. I'm doing > date-based boosting on the documents in my index, so as to assign a higher > score to more recent documents. Currently I'm using a boost function to > achieve this. I'm wondering if there would be a performance improvement if > instead of using the boost function at search time, I indexed the documents > with a date-based boost. > > On Fri, Jun 4, 2010 at 7:30 PM, Erick Erickson <erickerick...@gmail.com > >wrote: > > > Index time boosting is different than search time boosting, so > > asking about performance is irrelevant. > > > > Paraphrasing Hossman from years ago on the Lucene list (from > > memory). > > > > ...index time boosting is a way of saying this documents' > > title is more important than other documents' titles. Search > > time boosting is a way of saying "I care about documents > > whose titles contain this term more than other documents > > whose titles may match other parts of this query".... > > > > HTH > > Erick > > > > On Fri, Jun 4, 2010 at 5:10 PM, Asif Rahman <a...@newscred.com> wrote: > > > > > Hi, > > > > > > What are the performance ramifications for using a function-based boost > > at > > > search time (through bf in dismax parser) versus an index-time boost? > > > Currently I'm using boost functions on a 15GB index of ~14mm documents. > > > Our > > > queries generally match many thousands of documents. I'm wondering if > I > > > would see a performance improvement by switching over to index-time > > > boosting. > > > > > > Thanks, > > > > > > Asif > > > > > > -- > > > Asif Rahman > > > Lead Engineer - NewsCred > > > a...@newscred.com > > > http://platform.newscred.com > > > > > > > > > -- > Asif Rahman > Lead Engineer - NewsCred > a...@newscred.com > http://platform.newscred.com >
