title: When to combine multi-related/join tables
body: <p>Considering database performance, please review this example..</p>
  
  <p>If there are only 50,000 widgets in table one,two and three (total) and 50,000,000 widgets in table four. </p>
  
  <p>Using the following relational/join table to handle the first three relationships:</p>
  
  <pre><code>    ID (int)
      IndexID (int)
      RelationType (int)
      RelationID (int)
  </code></pre>
  
  <p>Would it be ok just to use this relational table for table four as well (by changing the relationtype to Table4), but considering it has a signifigantly larger amount of data than the first three tables?  Or should table four have its own relational/join table:</p>
  
  <pre><code>   ID (int)
     IndexID (int)
     RelationID (int)
  </code></pre>