Hello David, > Basecamp, Ta-da List, and Backpack were all managing > our real data shortly after the first SVN check-in. naah, you are exagerating here... You don't put real data on a project that you created 5 mins ago ;-) > The same change in an OTS system is a repeating two-step approach > where you first inform the database of the change, then say the same > to the domain model. Not really, the extra step takes half a minute max. And you don't change your schema regularily after you have inserted some real data. BTW, let me give you a real world example (your little video is not a real world case): Lets say you have a table with a column named body, and you want to rename this to description. Issuing the ALTER TABLE command takes hmm... 1 minute (I am always scared issuing ALTER TABLE on live data :-)) Adding the 1 line for Og takes 0.5 minute. Changing all your code to use the new name can take half an hour, ie an order of magnitude compared to the extra step needed in Og. So there is no problem in practice. But to keep you happy, I 'll have Og automatically issue the ALTER statement for most common cases. This will make the process even easier than AR: just do an SVN update on the live server and restart. No need to play with the live database and maybe make a dangerous mistake. > Some applications truly need that. Have a look at Typo's db directory, talk about DRY ;-) > Now what's much more interesting than OTS or STO is how to deal with > an evolving database scheme where you can't throw out the data on > ... > [1] http://www.martinfowler.com/articles/evodb.html Thanks for the interesting discussion. I 'll have a look at that article. best regards, George