Per, check zee Wiki, there is a page describing docvalues. We used them successfully in a solr for analytics scenario.
Otis Solr & ElasticSearch Support http://sematext.com/ On Sep 11, 2013 9:15 AM, "Michael Sokolov" <msoko...@safaribooksonline.com> wrote: > On 09/11/2013 08:40 AM, Per Steffensen wrote: > >> The reason I mention sort is that we in my project, half a year ago, have >> dealt with the FieldCache->OOM-problem when doing sort-requests. We >> basically just reject sort-requests unless they hit below X documents - in >> case they do we just find them without sorting and sort them ourselves >> afterwards. >> >> Currently our problem is, that we have to do a group/distinct (in >> SQL-language) query and we have found that we can do what we want to do >> using group >> (http://wiki.apache.org/solr/**FieldCollapsing<http://wiki.apache.org/solr/FieldCollapsing>) >> or facet - either will work for us. Problem is that they both use >> FieldCache and we "know" that using FieldCache will lead to OOM-execptions >> with the amount of data each of our Solr-nodes administrate. This time we >> have really no option of just "limit" usage as we did with sort. Therefore >> we need a group/distinct-functionality that works even on huge data-amounts >> (and a algorithm using FieldCache will not) >> >> I believe setting facet.method=enum will actually make facet not use the >> FieldCache. Is that true? Is it a bad idea? >> >> I do not know much about DocValues, but I do not believe that you will >> avoid FieldCache by using DocValues? Please elaborate, or point to >> documentation where I will be able to read that I am wrong. Thanks! >> > There is Simon Willnauer's presentation http://www.slideshare.net/** > lucenerevolution/willnauer-**simon-doc-values-column-** > stride-fields-in-lucene<http://www.slideshare.net/lucenerevolution/willnauer-simon-doc-values-column-stride-fields-in-lucene> > > and this blog post http://blog.trifork.com/2011/** > 10/27/introducing-lucene-**index-doc-values/<http://blog.trifork.com/2011/10/27/introducing-lucene-index-doc-values/> > > and this one that shows some performance comparisons: > http://searchhub.org/2013/04/**02/fun-with-docvalues-in-solr-**4-2/<http://searchhub.org/2013/04/02/fun-with-docvalues-in-solr-4-2/> > > > >
