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

From Hannu Krosing
Subject Re: xpath processing brain dead
Date
Msg-id 1235777871.7189.21.camel@huvostro
Whole thread Raw
In response to Re: xpath processing brain dead  (Andrew Dunstan <andrew@dunslane.net>)
Responses Re: xpath processing brain dead
Re: xpath processing brain dead
List pgsql-hackers
On Fri, 2009-02-27 at 16:37 -0500, Andrew Dunstan wrote:
> 
> Hannu Krosing wrote:
> > On Thu, 2009-02-26 at 13:51 -0500, Robert Haas wrote:
> >   
> >>> What I have proposed for 8.3 should not break a single case that currently
> >>> behaves usefully. If anyone has a counter-example please show it.
> >>>
> >>> What I have proposed for 8.4 possibly would break current "useful" behaviour
> >>> (FSVO "useful"), but should be done anyway on correctness grounds.
> >>>       
> >> I dunno, aren't XML document fragments sort of a pretty common case?
> >>     
> >
> > I'd rather argue that xml datatype should not even accept anything but
> > complete xml documents. Same as int field does not accept int[].
> >
> > Or maybe we rather need separate xmldocument and xmlforest/xmlfragments
> > types in next releases and leave the "base" xml as it is but deprecated
> > due to inability to fix it without breaking backwards compatibility.
> >
> >   
> 
> Some of the functions, including some specified in the standard, produce 
> fragments. That's why we have the 'IS DOCUMENT' test.

But then you could use xmlfragments as the functions return type, no ?

Does tha standard require that the same field type must store both
documents and fragments ?

> You can also force validation as a document by saying  SET XML OPTION 
> DOCUMENT;
> 
> cheers
> 
> andrew
-- 
Hannu Krosing   http://www.2ndQuadrant.com
PostgreSQL Scalability and Availability   Services, Consulting and Training



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