title: Oracle Materialized Views Vs Replication on the same DB server
body: <p>We need to run reports at a scheduled time of the day.
  The application runs 24*7 and so there is not "off-peak" time as such.</p>
  
  <p>Therefore, running the reports should not add undue load on the system.</p>
  
  <p>The application runs on WebSphere v6.1 and the database is Oracle 10g R2.</p>
  
  <p>I have the following approaches at my disposal</p>
  
  <ol>
  <li>A set of de-normalized tables aimed at reporting.</li>
  <li>Creating Materialized views and using them for reports. We can update the views once a day.</li>
  <li>We can create another schema and replicate the tables realtime using Oracle's Data Guard.</li>
  </ol>
  
  <p>(1) is not feasible due to certain internal constraints we have.</p>
  
  <p>I need to know, from a performance point of view, which is better, (2) or (3) ?</p>
  
  <p>I hear from many ppl that Materialized views initially work well but as data volumes increase, the
  performance is very poor.</p>
  
  <p>Anyone has experience with Replication of tables within the same DB server (but diff instances or schemas).</p>