[Zope] Zope Persistence (was: XML-RPC within ZOPE)

[Tino Wildenhain]

Am Samstag, den 17.12.2005, 14:56 +0100 schrieb Jan-Ole Esleben:
> > > That ZOPE raises an error is fine. That I _might_ run into such
> > > situations with other tools is true.
> > You *will* run into these problems in exactly the same cases in any other tool.
> 
> I'm sorry, but that's just wrong, and I have given examples of such
> situations. To simplify, in ZOPE, for any given product, during a
> transaction the product is effectively locked. So if I have, say, a
> list field that contains some data and a dictionary field that
> contains some other data, and the "internal" call changes the dict
> while the original call changes the list, that breaks the transaction,
> while in usual situation in a database, nothing would break.

This is wrong IMHO. dict and list are just columns of the same tuple
if you speak RDBMS. And there are very few (if any?) databases
which do locks only per column. In RDBMS you distribute in different
tables to avoid such (e.g. normalize) in ZODB, you just make
subclasses of Persistent for your subobjects. (Attributes)

HTH
Tino