title: Why does Magento have only three flat tables
body: <p>Why does Magetno have three flat tables? What specifically three (not two, not four)</p>
  
  <p>There's three for <code>catalog_category_flat</code></p>
  
  <pre><code>catalog_category_flat_store_1
  catalog_category_flat_store_2
  catalog_category_flat_store_3
  </code></pre>
  
  <p>and three for <code>catalog_product_flat</code></p>
  
  <pre><code>catalog_product_flat_1
  catalog_product_flat_2
  catalog_product_flat_3
  </code></pre>
  
  <p>Why?</p>