Re: xpath processing brain dead

On Sun, 2009-03-01 at 18:22 -0500, Andrew Dunstan wrote:

> I think the XML type needs to conform to the SQL/XML spec. However, we
> are trying to apply XPath, which has a different data model, to that 
> type - hence the impedance mismatch.
> 
> I think that the best we can do (for 8.4, having fixed 8.3 as best we 
> can without adversely changing behaviour) is to throw the
> responsibility 
> for ensuring that the XML passed to the function is an XML document
> back on the programmer. Anything else, especially any mangling of the
> XPath 
> expression, presents a very real danger of breaking on correct input.

Can we provide a single function to bridge the gap between fragment and
document? It will be clearer to do this than to see various forms of
appending/munging, even if that function is a simple wrapper around an
append.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support