Chris Withers wrote:

...

I want to develope a forum with zope. There are products wich store messages and replies in the ZODB. In case this forum will become crowded, this seems to me not the right way ( ? ). I've read that ZODB does a good job if 99% of the users only read.

Mostly rubbish, try Squishdot: http://www.squishdot.org

I know of people with 2000-6000 postings and no problems.

...

Is this right? Can somebody tell me at wich "size" (e.g. amount of users, hits, etc... ) an external db is needed?

...hardly ever, IMNSHO.

I agree with Chris. I have done testing with tens of thousands of objects and the only time I see performance hits is with the management interface (the tree code I believe). If you have a custome interface that doesn't have to resolve all those objects at one time there is no problem. AFAIK the references to 'many writes vs. reads' applies on a per object basis. In an application like Squishdot or FreePM where a particular object is seldom if ever changed there is no problem. The issue regarding the number of writes is caused by the undo feature. You create a new copy of the object when you edit it. When used for the correct application, the ZODB is very robust. Cheers, -- Tim Cook, President - Free Practice Management, Inc. http://www.FreePM.com Office: (731) 884-4126 ONLINE DEMO: http://www.freepm.org:8080/FreePM