[ZODB-Dev] Perennity of ZODB format

[Dieter Maurer]

Pierre-Yves Delens wrote at 2004-9-24 08:51 +0200:
> ...
>> Q.1 Do you have docs about the ZODB datas-format :

The ZODB stores Python objects as (Python) pickles.
Python tries hard to keep the pickle format compatible
(such that newer version can still understand older pickles).
I think, that up to now, there has not been a compatibility problem.

How a storage manages the pickles (more precisely, the OID to pickle
(and additional info) map) is decided by the storage.
At the start of the "FileStorage" implementation is the desciption
for the formats used by "FileStorage".

> ...
>differences between
>ZODB releases, good practices, roadmap, or whatever ?

This sounds a bit confusing...

>> Q.2 I Will store datas partially in XML, or at least have to serialize and
>tranform to XML.

Usually not -- because XML is a quite expensive serialization format.

Zope provides the feature to export ZODB objects in an XML format.

But, don't be fooled: the fact that something is XML serializable
does not mean that it is easier to reconstruct that when a
different (more efficient) serialization format is used.

>   >>> Among the vast choice of Python tools for XML, do you know about best
>choices for working in ZODB ?

The ZODB is completely unconcerned which XML processing tools
you use for your application.


The Zope XML import uses "pyexpat" to parse the XML.

-- 
Dieter