Gang, We've got an indexed solr.DateField that we'd like to use for sorting our query results. In January, Mike Klaas suggested turning on <useFilterForSortedQuery> to make sorting search results on a field efficient:
At 4:18 PM -0800 1/31/08, Mike Klaas wrote: >The situation could be optimized in Solr, but there is a related case that >_is_ optimized that should be almost as fast. If you > >a) don't ask for document score in field list (fl) >b) enable <useFilterForSortedQuery> in solrconfig.xml >c) specify _some_ sort order other than score > >Then Solr will do cached bitset intersections only. It will also do sorting, >but that may not be terribly expensive. If it is close to the desired >performance, it would be relatively easy to patch solr to not do that step. > >(Note: this is query sort, no facet sort). However, it sounds like the original motivation for <useFilterForSortedQuery> was to overcome performance problems and bugs in older versions of Lucene using multi-segment indices: At 18:03 PM -0400 12/11/06, Yonik Seeley wrote: >People may want to consider changing the useFilterForSortedQuery >option from true to false (or commenting it out) in solrconfig.xml >I believe it should result in a speedup for the average query that >sorts on something other than score. >Generating and using filters for base queries used to be a win due to: >1) a set of complex queries that were almost never sorted by score, >but the sort changed >2) bugs/slowness in Lucene when dealing with multi-segment indicies >The deficiencies in Lucene have been corrected, and the introduction >of fq filter parameters that are cached separately go a long way >toward mitigating #1. The downside to this optimization is extra >work when the same base query isn't resorted often, and pollution of >the filterCache. I've changed the default to false for the example >solrconfig.xml For the moment, our solrconfig.xml looks like the example one (i.e., useFilterForSortedQuery is commented out). Thanks in advance for any advice, - Chris -- ---------------------------- Chris Schneider Krugle, Inc. http://www.krugle.com [EMAIL PROTECTED] ----------------------------
