[Zope] minimizing conflict errors

[Dennis Allison]

I have a DTML method which provides the primary navigation control in a 
portion of our system and so is very heavily used.  It is a primary source
of conflict errors and so is being rethought.

Zope 2.8.4, ZEO 3.4.2, ZODB 3.4.2, Python 2.4.2 or 2.3.5 
MySQL 4.0.20, MySQL-Python 1.2.0, MYSQLDA 2.0.9

ZODB 3.4.2 does not raise a conflict error on a read-read conflict, one of 
the reasons fr moving to Zope 2.8.4.

The structure of the naviagation method is simple enough. Everything is 
wrapped in a <dtml-let> which sets a number of parameters mostly by 
reading them from the SESSION (with an interface function) or plucking 
them from the relational database with a query.

In the scope of the let is dtml code which, when rendered, provides the 
various navigation links.  In various sections there are additional 
<dtml-let> blocks and additional queries to the relational database
and several <dtml-in> loops.

Looking at the code, I don't understand why I am seeing conflicts.
As I understand things, neither variables in the <dtml-let> space nor
the REQUEST/RESPONSE space are stored in the ZODB so modifications to 
them don't look like writes to the conflict mechanism.  Am I incorrect 
in my understanding?