title: Oracle-Update is very slow
body: <p>Here is my update statement:</p>
  
  <pre><code>Update childtbl C 
      set C.chldFld=Select P.ParentFld 
                    from ParentTbl P 
                    where P.ID=C.ID
  </code></pre>
  
  <p>It is taking hours and hours to update.</p>
  
  <p>There are indexes for both the parent and child tables.</p>