Hi Anand, Mikhail writes about different join solutions and compares them. Here is couple of his write-ups.
http://blog.griddynamics.com/2012/08/block-join-query-performs.html http://blog.griddynamics.com/2013/09/solr-block-join-support.html On Saturday, February 1, 2014 9:18 AM, anand chandak <anand.chan...@oracle.com> wrote: Folks, have a basic question regarding solr join, the wiki, <http://wiki.apache.org/solr/Join> states : - "Fields or other properties of the documents being joined "from" are not available for use in processing of the resulting set of "to" documents (ie: you can not return fields in the "from" documents as if they were a multivalued field on the "to" documents)". I am finding it hard to understand the above limitation of solr join,does it means that unlike the traditional RDMS joins that can have columns from both the TO and FROM field, solr joins will only have fields from the TO documents ? Is my understanding correct ? Also, there's some difference with respect to scoring and towards that the wiki says : "The Join query produces constant scores for all documents that match -- scores computed by the nested query for the "from" documents are not available to use in scoring the "to" documents" Does it mean the subquery's score is not available the main query? Is this behaviour true for the lucene join too ? Basically, i am trying to understand where and how solr joins differ from lucene joins. Any pointers, much appreciated ? I have posted same question on the stackoverflow <http://stackoverflow.com/questions/21480628/solr-join-vs-lucene-join> Thanks, Anand
