title: Query working in SQLPlus and SQLDeveloper but not through JDBC
body: <p>I have Oracle database 12.1.0.2.0 installed with <code>parallel_min_percent</code> set to 50. (Other params are <code>parallel_min_servers = 24</code>, <code>parallel_max_servers = 48</code>)</p>
  
  <p>I am trying to run below query and getting exception:</p>
  
  <pre><code>select constraint_name, constraint_type, table_name 
   from user_constraints where table_name = ? AND constraint_type = 'P';
  </code></pre>
  
  <p><code>Table_name</code> is set to <code>'employee'</code>.</p>
  
  <p>Note:</p>
  
  <ol>
  <li>I am not getting any error while running this query from sqlplus or sqldeveloper.</li>
  <li>Error is observed only while running using JDBC</li>
  <li>I am not getting any error if I remove <code>constraint_type = 'P'</code> clause</li>
  </ol>
  
  <blockquote>
    <p>Exception: ORA-12827: insufficient parallel query slaves (requested 2,
    available 0, parallel_min_percent 50)</p>
  </blockquote>
  
  <p>How do I get it working in case of JDBC?</p>
  
  <p>Also, is there a way, i can check degree of user_constraint table?</p>