Maybe what you are looking for is DatastoreService.allocateIds().
On Oct 21, 9:35 am, leszek <leszek.ptokar...@gmail.com> wrote:
> 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...
>
> 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
-~----------~----~----~----~------~----~------~--~---
