If you are unhappy with the performance overhead of a function boost, you can push it into a field query by boosting date ranges.
You would group in date ranges: documents in September would be boosted 1.0, October 2.0, November 3.0 etc. On 6/5/10, Asif Rahman <a...@newscred.com> wrote: > Thanks everyone for your help so far. I'm still trying to get to the bottom > of whether switching over to index-time boosts will give me a performance > improvement, and if so if it will be noticeable. This is all under the > assumption that I can achieve the scoring functionality that I need with > either index-time or search-time boosting (given the loss of precision. I > can always dust off the old profiler to see what's going on with the > search-time boosts, but testing the index-time boosts will require a full > reindex, which could take days with our dataset. > > On Sat, Jun 5, 2010 at 9:17 AM, Robert Muir <rcm...@gmail.com> wrote: > >> On Fri, Jun 4, 2010 at 7:50 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. >> > >> > >> Asif, without knowing more details, before you look at performance you >> might >> want to consider the relevance impacts of switching to index-time boosting >> for your use case too. >> >> You can read more about the differences here: >> http://lucene.apache.org/java/3_0_1/scoring.html >> >> But I think the most important for this date-influenced use case is: >> >> "Indexing time boosts are preprocessed for storage efficiency and written >> to >> the directory (when writing the document) in a single byte (!)" >> >> If you do this as an index-time boost, your boosts will lose lots of >> precision for this reason. >> >> -- >> Robert Muir >> rcm...@gmail.com >> > > > > -- > Asif Rahman > Lead Engineer - NewsCred > a...@newscred.com > http://platform.newscred.com > -- Lance Norskog goks...@gmail.com
