ou've 
&gt; been making an 
&gt; efficiency claim that one can't have too many sorts of 
&gt; constraint checks on 
&gt; a DB because it's too inefficient.  On the other hand you 
&gt; offer &quot;eyeball 
&gt; the resultant data&quot; as a solution, which I would think would 
&gt; be impractical 
&gt; if the data set is so large that automated constraint 
&gt; checking is an issue.

MW: You only need to eyeball a sample of the data. When you see
that 2 or 3 rows have the data transposed, and you know a sys