title: Oracle: How to find the timestamp of the last update (any table) within a schema?
body: <p>There is an Oracle database schema (very small in data, but still about 10-15 tables). It contains a sort of configuration (routing tables).</p>
  
  <p>There is an application that have to poll this schema from time to time. Notifications are not to be used. </p>
  
  <p>If no data in the schema were updated, the application should use its current in-memory version. </p>
  
  <p>If any table had any update, the application should reload all the tables into memory.</p>
  
  <p>What would be the most effective way to check the whole schema for update since a given key point (time or transaction id)?</p>
  
  <p>I am imagined Oracle keeps an transaction id per schema. Then there should be a way to query such an ID and keep it to compare with at next poll.</p>
  
  <p>I've found this question, where such an pseudo-column exists on a row level:</p>
  
  <p><a href="https://stackoverflow.com/questions/265122/how-to-find-out-when-an-oracle-table-was-updated-the-last-time">How to find out when an Oracle table was updated the last time</a></p>
  
  <p>I would think something similar exists on a schema level.</p>
  
  <p>Can someone please point me in the right direction?</p>