title: How much memory maps are consuming?
body: <p>I have a xquery for report generation which holds at times around 500K uris in a map and check for their existence(<code>cts:search</code> with <code>cts:document-query</code>) in database and return the diff. However there is slow down in response time, if we hit the same E-node with concurrent requests. </p>
  
  <p>Is there any upper limit on the memory size maps can consume?
  In any case can maps be swapped to disk?</p>