title: How to make the Oracle jdbc driver jar available to jenkins pipeline script on a slave
body: <p>I'm trying to write a pipeline script that runs a query on an oracle db.  I have a slave where I've installed the Oracle JDBC driver jar.</p>
  
  <p>In global settings on the master, I've set the "Additional groovy classpath" field to the path to the driver jar on the slave.</p>
  
  <p>I then ran my pipeline script, which so far is very simple:</p>
  
  <pre><code>import groovy.sql.Sql;
  
  node ("sqlplus") {
      stage ("RUN QUERY") {
          def sql = Sql.newInstance("jdbc:oracle:thin:@...", "..", "..", "oracle.jdbc.driver.OracleDriver")
           query = "SELECT count(*) from ..."
           println sql.rows(query)
           sql.close() 
      }
  }
  </code></pre>
  
  <p>This compiles, but it fails with "java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver".</p>
  
  <p>So, do I have to restart something to get this to work, or is this not going to work the way I'm expecting?</p>