[Zope] - ZODB XML import/export

[Jim Fulton]

Jeff Bauer wrote:
> 
> Andrew's discussion about multiple databases got me
> thinking again about XML import/export capability for
> the Zope database.  I think an object database for
> Python has broader implications for Python programmers
> that extend beyond using it with Zope.  And having an
> ability to analyze a database independent of the application,
> independent of transactions, etc., makes XML import/export
> a compelling feature.
> 
> A few questions/conjectures.
> 
> - Is there any kind of baseline DTD that will be designed
>   for simple pickles? 

I think that there are a number of XML pickling formats
around.  I don't know if any of them are powerful 
enough to provide the generality of Python pickles.

There's been a lot of discussion of this on the XML-SIG
list recently, but I haven't had the bandwidth to follow it.

Andrew, wanna make any observations here?

I'd really like to see a converter from python pickles to
some XML "pickle" format and the other way around.
If someone provided such a beast, it would be straightforward
to implement an XML export/import tool.

>   If so, will the Zope Object Database
>   DTD be an extension of the same?

I doubt it, if only for performance reasons.  In normal
operations, the database needs to be able to pickle and
unpickler objects *very* quickly.  I seriously doubt that
any XML-based tool will ever come within an order of 
magnitude in speed of cPickle.
 
> - Not knowing anything about the ZODB release schedule, I
>   think that simply having a release that supports XML export
>   capability alone would be worth having (nudge, nudge) if
>   XML import requires more time to implement.

A converter from pickle format to XML would move things 
along nicely. (nudge nudge)
 
> - Is a staged build of a Zope system

What's a "staged build"?

>   using XML import
>   capability a likely scenario?  By this I don't mean
>   is it *possible*, I'm asking if it will probably
>   someday be considered a routine way to accomplish
>   this kind of task.

There is now a facility for loading product state from 
export files as part of product installation.
Is this the sort of thing you are talking about?
 
> - Are we likely to see the Zope Object Database used
>   independently of Zope, i.e. where an object database
>   may be desired (pickles + concurrent transactions) ?

I hope so.

>   I'm not aware of anyone who used BoboPOS in this manner.
> 
> - What's the preferred acronym for the Zope Object
>   Database?  ZODB?

Hm. Good question.  I guess I'd be inclined to say yes.
I guess the current version is ZODB 2 and the next version
(the thing FKA BoboPOS3) is ZODB 3.  Paul may correct me on this.

Jim

--
Jim Fulton           mailto:jim@digicool.com
Technical Director   (888) 344-4332              Python Powered!
Digital Creations    http://www.digicool.com     http://www.python.org

Under US Code Title 47, Sec.227(b)(1)(C), Sec.227(a)(2)(B) This email
address may not be added to any commercial mail list with out my
permission.  Violation of my privacy with advertising or SPAM will
result in a suit for a MINIMUM of $500 damages/incident, $1500 for
repeats.