Database Table & Field Changes (1.3 to 1.4)

[Joe Germann]

I am in the midst of upgrading from 1.3 to 1.4 and in general am quite impressed with the changes. I do something very different with PrestaShop in that I manage most of the back end using another database application via ODBC connections.

Is there any specification documentation for the database structure which describes the fields and their use? There are a lot of differences in the DB structure from 1.3 to 1.4. For the most part I can figure out what they mean and do, but there are a few I have yet to decipher..

Can anyone tell me the meaning and how the following fields are used in 1.4? They were not in 1.3.

ps_category::nleft
ps_category::nright

I am sure I'll find a few more but help with these would be great.

Thanks,
Joe