You hit the nail on the head. As far as I know there is nothing like "sequence" in Google App Engine. Either you need to have another entity with a counter and increase it in transactional way. Or you can use memcache.
http://code.google.com/intl/pl/appengine/docs/java/javadoc/com/google/appengine/api/memcache/MemcacheService.html There is a method: -------- java.lang.Long increment(java.lang.Object key, long delta) Atomically fetches, increments, and stores a given integral value. ------- Pay attention to "atomically". May be this can be used for generating sequential and avoid bottleneck in the case of datastore entity and additional transaction. But because of the risk of memcache expiring this method needs some more elaboration. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~----------~----~----~----~------~----~------~--~---
