title: SOLR: What is the need for both query and filter query?
body: <p>With boolean expressions, the query parameter alone <code>q=...</code> can get the data you need. Alternatively with <code>q=*:*</code> the filter query fq could have the same parameters and achieve much of the same result. </p>
  
  <p>I've always applied the second solution with <code>q=*:*</code> while having filter query "fq" for all, knowing that there is some filter query cache going on. So, why the need for both? Is always using fq for queries the correct way to go?</p>