On Sun, Nov 23, 2008 at 8:50 AM, Andy Freeman <[EMAIL PROTECTED]> wrote:
>> > Suppose that I want to atomically create an entity group with two >> > nodes, one the parent of the other. >> But *why* exactly do you want to do this? > > Because I want "a set of one or more entities that can be manipulated > in a single transaction. Entity group relationships tell App Engine to > store several entities in the same part of the distributed network. A > transaction sets up datastore operations for an entity group, and all > of the operations are applied as a group, or not at all if the > transaction fails." Yes, I understand transactions and entity groups. Why do you need to create an entity group *atomically*? > The fact that GAE uses many machines and concurrently is why the full > hostname, IP, or MAC address or some other machine identifier is > useful in creating a unique identifier on GAE. (If my application > always ran on the same machine, the process id and time would be > sufficient.) If you create a new entity, it will automatically be assigned a unique key at the datastore level. What's wrong with just using that? Dave. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
