title: Search across multiple cores and get unified result
body: <p>I have 2 cores on a single solr instance. Schema's of both cores share same primary key.
  I want to merge results of a query from both the cores. Is it possible using solr? </p>
  
  <p>I followed <a href="http://wiki.apache.org/solr/DistributedSearch" rel="nofollow">Solr:Distributed Search</a>  however the example didnt work for me ( I did get result but it was not unified) . I queried solr cores using : </p>
  
  <blockquote>
    <p>localhost:8983/solr/core1/select/?shards=localhost:8983/solr/core1,localhost:8983/solr/core0&amp;q=123_456.</p>
  </blockquote>
  
  <p>Has anyone tried this approach before?</p>