[Zope-dev] Re: ZCatalog and Unique IDs

Chris Withers chrisw@nipltd.com
Thu, 25 May 2000 11:22:39 +0100


Michel Pelletier wrote:
> >
> > I hope this is a stupid question but why does ZCatalog use the URL of an
> > object to uniquely identify it?
> 
> Because it's unique.

I think that depends on how you define a URL.

For me:

/Site/object1

/object1

/Site/Site/Site/Site/object1

are all URLs, in a ZCatalog sense, that point to the same object and
aren't very unique ;-)

I agree the path from root to an object, with no aquisition, is unique,
but only per instance of zope...

> > Persistent object
> > identifiers must exist for the ZODB so why not use them instead?
> 
> They change, I believe, over the revisions of the objects; and also this
> is a very low level identifier.  I'm not certain.  I think this
> attribute is _p_oid.

I was thinking along the lines of a CORBA POID which, AFAIK, uniquely
identifies an object on a global scale. Could Zope do something similar? 

> > PS: This would solve all the problems with ZCatalogs and virtually
> > hosted sites...
> 
> So would a solid traversal interface that understood virtual hosting in
> Zope.

agreed... ;-)

Well, here's hoping it makes it into 2.2, I'd be interested to here
people's views on the CORBA POID idea though...

Chris