Friday May 18, 2012

Core Data Transaction Logs

I know I linked to Drew’s series already, but his second installment is just so great. If you do anything with Core Data at all, you need to read these posts.

In other words, where with MobileMe there was a single truth database in the cloud, there is now just a collection of transaction logs from different devices, and a number of clients doing their best to independently reconcile those logs. As long as the updates are reasonably distinct, it works well, but when changes overlap considerably, you can get quite tricky situations. A lot of the discussion in this series of posts revolves around working around the conflicts that can arise.