title: nested exists clauses vs adjacent exists clauses
body: <p>Can someone please tell me which of this 2 querys is better than the other and why?
  Should I use a join instead?</p>
  
  <pre><code>select * from grandChildTable gct
  where exists(
      select * from childTable ct
      where some condition
      and gct.parentId = ct.Id
      and exists(
          select * from Table t
          where some other condition
          and ct.parentId = t.Id))
  
  select * from grandChildTable gct
  where exists(
      select * from childTable ct
      where some condition
      and gct.parentId = ct.Id)
  and exists(
      select * from Table t
      where some other condition
      and gct.grandParentId = t.Id)
  </code></pre>
  
  <p>NOTES:
  The <code>GrandChildTable</code> has the IDs for both the <code>ChildTable</code> and <code>Table</code> because the IDs are compound.</p>
  
  <p>The tables doesn't have references to any of the others.</p>
  
  <p>The relationships between the tables are:</p>
  
  <pre><code>GrandChild to Child
  n:1
  
  Child to Table
  n:1
  </code></pre>