title: Postgres: "ERROR: cached plan must not change result type"
body: <p>This exception is being thrown by the PostgreSQL 8.3.7 server to my application.
  Does anyone know what this error means and what I can do about it?</p>
  
  <pre><code>ERROR:  cached plan must not change result type
  STATEMENT:  select code,is_deprecated from country where code=$1
  </code></pre>