On Jun 10, 5:21 pm, Tony <fatd...@gmail.com> wrote: > The biggest question I wished I'd asked myself before designing my app > is: "what sorts of models will I want to update together in > transactions?" Because in Datastore you can only run transactions on > entities in the same entity group (meaning each entity is an ancestor/ > child of the others). So if you need certain operations to maintain > consistency, for instance "add new Turn entity, update Game's > current_player" you will need to plan that ahead of time (perhaps > assigning each Turn as a child of the Game it takes place in).
Right, I came to the same conclusion. The game's state is the only "super-entity" that needs to be updated atomically, so I decided to group it together. > Other than that, just remember that writing to Datastore is very > expensive (as is fetching large numbers of entities from a query) - > you will want to figure out ways to retrieve entities by key as much > as possible. I'll keep that in mind. It would be nice to have some "rule of thumb" advice on when and how to use memcache. Thanks, -n8 --~--~---------~--~----~------------~-------~--~----~ 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 google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
