Hello there, I have written a bunch of stuff against google app engine over the past year and have played lots of data games. let's see if i can provide a little insight.
- first off, the CSV download functions only work while the tables are small (under a few thousand rows). after that look at the google app engine bulkloader tools. note that there is no automated way to download and restore data from the blobstore (that is on my todo list for this month though....) - i don't know how you did your model, but if you just added new fields to existing tables then just deploy it! no seriously, GAE gracefully will just add the new columns. note that if you want to query old data using those columns in filters you will have to iterate through the old data and set defaults. - if you need defaults, you should consider using the taskqueue for this. it allows jobs to run up to 10 minutes now. while not 100% safe i sort on ID and get batches of a rows at a time to work with. (when the limit was 30 seconds i found i could query and update about 100 rows in that time) - shhhh, don't tell, but as far as i can tell the ID if autogenerated on GAE is unique to the database, not just the table/model, but please test my theory heavily before depending on it. hopefully that helps a little. feel free to ask more. christian
