[Zope3-Users] Zope3 with RDBMS (avoiding ZODB)?

[Stefan Krumbiegel (Galileo Press)]

Hi all,

our applications are actually running on Zope2. Now we are planning to 
change
the framework to a modern MVC-style one. It will be a reimplementation 
of our
applications from scratch. Two candidates are left over: Zope3 and Django.
(We have already built a simple CMS with Django... it worked very well,
is smart and fast.)

Now we have some fundamental questions about Zope3. We would be very pleased
if someone can help us finding the right solution for us.

1. Is Zope3 already in use in productive environments? Where are they 
(URLs)?

2. Are there any bigger sites running on Zope3 (> 5 mio. accesses per 
month)?

3. Our main problem is: in our Zope2-application we stored our content in a
RDBMS, we avoided ZODB for that stuff. We are definitely going to use an 
RDBMS
(PostgreSQL/MySQL) for the new (Zope3 or Django)-project and still want 
to avoid
ZODB where possible. This architectural decision is carved out of stone.

Now, where should we start with it in Zope3 to connect it to an RDBMS?

3.1 We have found 'PostGreSQL Database Adapter' and 'MySQL Database
Adapter'. Both are from the Isar sprint (2004-11-06). Are they out of date,
or just 'nearly perfect'? Is anybody using these adapters?

3.2 sqlos - SQLObject Support package (http://codespeak.net/z3/sqlos/):
Is it stable? Has someone experiences with it?
In http://mail.zope.org/pipermail/zope3-users/2006-January/001797.html
Stephan Richter says: "On the other hand, not many people use sqlos, so
it might not be as supported as you wish it would be." Is that still right?

3.3 Also there is 'zsqlmap: Zope3 wrapper for SQLObject'
(http://www.zope.org/Members/garanin/zsqlmap). This is not really a
solution for us because the version number is 0.01b and the author says:
'NOTE: i tested only postgres.' Not really a capable product...

4. Has anybody practical experience and hints with Zope3 and RDBMS?

5. The ZMI: In Zope2 we never used it.
Do we need the ZMI in Zope 3 just if we will not use the ZODB for 
storing our
content objects but an RDBMS instead. According to 'Web Component 
Development
with Zope 3' by Philipp von Weiterhausen the ZMI is used to manage 
content objects
stored in the ZODB, so our assumption is, if we do not store them in the 
ZODB,
we do not need the ZMI. Is that right or do we need the ZMI for anything 
else?
Do we need ZMI in Zope3 for administration or can we do that with 
scripts etc.?

6. Last but not least two quotes from the zope3-dev mailinglist
(http://mail.zope.org/pipermail/zope3-dev/2006-February/018217.html):
> >Shane Hathaway wrote:
>> >> It could
>> >> turn out that people who don't want ZODB really shouldn't use Zope at
>> >> all.
> >This has been the case in my experience...
> >Chris Withers
...
Discussion 'Zope 3 without ZODB' in the zope3-dev mailinglist
(http://www.mail-archive.com/zope3-dev@zope.org/msg07517.html):
> >... I expect that such an application would look a lot like
> >applications built with other web frameworks.
> >Jim Fulton

What do you say about that? Does that mean that we should definitively
not use Zope3 if we don't want to use the ZODB but our RDBMS instead?

Thanks a lot!
Best regards
Stefan