oodb philosophics ;) was: Re: [Zope-dev] Experiments with ORMapping

[Shane Hathaway]

Tino Wildenhain wrote:
> I think the motivation people want an RDBMS storage beneth zodb is
> because they understand RDBMSes these days are performant, relieable
> and can quiete easy maintained.

The other motivations for an RDBMS are (1) people have existing schemas
and want Zope to access the same data as their existing apps, and they
want it to be transparent, and (2) tables with millions of entries are
easily stored in Zope but the perception is that the catalog isn't as
fast as a database index.  No one has done any tests AFAIK.

> I've seen Java implementations using this approach to achive persistens
> using as example "Powertier[tm]" to explicit map oop data to an RDBMS.
> I didnt like it because you have to map your objects each time you create
> a class, keep in mind not to infere with others etc...

That's one reason ZODB is so nice.  You can write an application without
writing a formal schema.

> Would it not be better to improve the abilities of the Filestorage
> to handle updates better? May be most of the storage system in C?
> With logfiles like modern RDBMSes use to incorporate fast changes?
> However, to avoid pickling/unpickling and may be to update on
> attribute-change, we need the approach you mentioned.
> 
> What about using a real oodb for zope? Dont remember any particular
> product name, but I heard something.

Actually OracleStorage and bsddbstorage, recently released, are designed
to address concerns about performance and reliability, and they do an
excellent job at it.  And I consider ZODB as "real" an OODB as anything
else.  (In some ways it's the best out there IMHO.)

Shane