Perhaps this can help you make sense of the advantages...
https://cwiki.apache.org/confluence/display/solr/DocValues : Date: Wed, 20 Nov 2013 18:45:04 +0800 : From: Floyd Wu <floyd...@gmail.com> : Reply-To: solr-user@lucene.apache.org : To: solr-user@lucene.apache.org : Subject: Re: DocValues uasge and senarios? : : Thanks Yago, : : I've read this article : http://searchhub.org/2013/04/02/fun-with-docvalues-in-solr-4-2/ : But I don't understand well. : I'll try to figure out the missing part. Thanks for helping. : : Floyd : : : : : 2013/11/20 Yago Riveiro <yago.rive...@gmail.com> : : > You should understand the DocValues as feature that allow you to do : > sorting and faceting without blow the heap. : > : > They are not necessary faster than the traditional method, they are more : > memory efficient and in huge indexes this is the main limitation. : > : > This post resumes the docvalues feature and the main goals : > http://searchhub.org/2013/04/02/fun-with-docvalues-in-solr-4-2/ : > : > -- : > Yago Riveiro : > Sent with Sparrow (http://www.sparrowmailapp.com/?sig) : > : > : > On Wednesday, November 20, 2013 at 10:15 AM, Floyd Wu wrote: : > : > > Hi Yago : > > : > > Thanks for you reply. I once thought that DocValues feature is one for me : > > to store some extra values. : > > : > > May I summarized that DocValues is a feature that "speed up" sorting and : > > faceting? : > > : > > Floyd : > > : > > : > > : > > 2013/11/20 Yago Riveiro <yago.rive...@gmail.com (mailto: : > yago.rive...@gmail.com)> : > > : > > > Hi Floyd, : > > > : > > > DocValues are useful for sorting and faceting per example. : > > > : > > > You don't need to change nothing in your xml's, the only thing that you : > > > need to do is set the docValues=true in your field definition in the : > schema. : > > > : > > > If you don't want use the default implementation (all loaded in the : > heap), : > > > you need to add the tag <codecFactory : > class="solr.SchemaCodecFactory"/> in : > > > the solrconfig.xml and the docValuesFormat=true on the fieldType : > definition. : > > > : > > > -- : > > > Yago Riveiro : > > > Sent with Sparrow (http://www.sparrowmailapp.com/?sig) : > > > : > > > : > > > On Wednesday, November 20, 2013 at 9:38 AM, Floyd Wu wrote: : > > > : > > > > Hi there, : > > > > : > > > > I'm not fully understand what kind of usage example that DocValues : > can be : > > > > used? : > > > > : > > > > When I set field docValues=true, do i need to change anyhting in xml : > > > that I : > > > > sent to solr for indexing? : > > > > : > > > > Please point me. : > > > > : > > > > Thanks : > > > > : > > > > Floyd : > > > > : > > > > PS: I've googled and read lots of DocValues discussion but confused. : > : > : -Hoss
