Re: xpath processing brain dead - Mailing list pgsql-hackers

From Hannu Krosing
Subject Re: xpath processing brain dead
Date
Msg-id 1236003157.7911.11.camel@huvostro
Whole thread Raw
In response to Re: xpath processing brain dead  (Peter Eisentraut <peter_e@gmx.net>)
List pgsql-hackers
On Mon, 2009-03-02 at 15:25 +0200, Peter Eisentraut wrote:
> Hannu Krosing wrote:
> > Is it just that in you _can't_ use Xpath on fragments, and you _need_ to
> > pass full documents to Xpath ? 
> > 
> > At least this is my reading of Xpath standard.
> 
> It is easy to read the XPath standard that way, because the concept of 
> fragments is not defined outside of SQL/XML, and is therefore unknown to 
> the XPath standard. 

How is the opposite - Does SQL/XML specify Xpath usage for XML(SEQUENCE)
and XML(CONTENT) ?

>  The question at hand is rather whether we can 
> usefully adapt it.

This sounds like trying to adapt integer arithmetic to
lists-of-integers.

Even for simple things like addition, there are several ways of doing it

[1,2,3] + [1,1,1] = [1,2,3,1,1,1]
[1,2,3] + [1,1,1] = [2,3,4]
[1,2,3] + [1,1,1] = [[1,2,3],[1,1,1]]

all seem possible and "logical"


-- 
Hannu Krosing   http://www.2ndQuadrant.com
PostgreSQL Scalability and Availability   Services, Consulting and Training



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