Обсуждение: Mapping arbitriary and heirachical XML to tuple

I have a system by which I store complex data in PostgreSQL as an XML
string. I have a simple function that can return a single value.

I would like to return sets and sets of rows from the data. This is not a
huge problem, as I've written a few of these functions. The question I'd
like to put out there, is how would you represent heirarchical data as:

<foo> <bar>   <ndx>0</ndx>   <val>1.00</val>   <meta>2.5</meta>   <froboz>3.5</froboz>   <klude>       <item>5</item>
   <life>10</life>   </kludge> </bar> <bar>   <ndx>1</ndx>   <val>1.10</val>   <meta>2.2</meta>   <froboz>3.53</froboz>
 <klude>       <item>3</item>       <life>9</life>   </kludge> </bar>
 
</bar>


The biggest problem with XML is storing data is easy, getting it back out
in a sane way is less so. How would you guys think to represent this?
(Obviously, this is a bogus example, real life would be much worse!)