title: MySQL slow copy from one to another table
body: <p>I copied files from one database to another using the following statement:</p>
  
  <pre><code>INSERT INTO database1.table Select ... FROM database2.table
  </code></pre>
  
  <p>It works all fine but is really really slow. For 400.000 datarows (about 600mb) it took me a couple of hours.</p>
  
  <p>I am using an MyISAM table to do it.</p>
  
  <p>My primary key is a unique identifier which is build out of different datafields.</p>
  
  <p>Could I speed up the copying process by adding a new column which uses an unique identifier, let's say an integer which begins at 1 and goes to the last row and make it an AUTO_INCREMENT which also goes up when copying the files?
  Or maybe setting an index on the new column?</p>
  
  <p>I am really happy if you can help me speed up the copy process.</p>