I'm wondering of there is a good question here: what precisely is the advantage of using postgres to mysql for Dotlrn? My understanding is that postgre does transactions and so insures data integrity in a way that mysql can not. Might others remind us of other reasons? And for that matter, what is the advantage of going to the expense of using Oracle? Has anyone written this up in a way that might help those involve in setting up our systems and marketing? In advance, Thanks!