Malte,
Finally we found a way to manage problems due dotlrn parameters (community_level_p, community_type_level_p and dotlrn_level_p) being set to NULL after upgrade.
We tried this solution with recent upgrades we did from dotlrn-2.1.1 to dotlrn-2.2.0a3 and dotlrn-2.1.3 to dotlrn-2.2.0a3, using postgresql
We just create an auxiliary table with sql upgrade script to preserve old parameters values stored in apm_parameter_values and introduced a callback in dotlrn/tcl/apm-callbacks.tcl. This callback is responsible to copy attr_values from auxiliary table to apm_parameter_values after upgrade.
It works for us and upgrade was made easy. Community portals are showed after upgrade and besides not all aplications were fully tested yet we think this solution could be interesting.
We will continue this week looking at dotlrn installations we upgraded searching for bugs or inconvenients after upgrade and testing packages for dotlrn-all. I will post a patch for dotlrn with our suggestion so you could appreciate. Nima, your considerations would be great too.
Patch for bug:
https://openacs.org/bugtracker/openacs/bug?f%5fcomponent=56129&format=table&f%5fstate=7&bug%5fnumber=2717&project%5fid=56106
