You can use Distributed Transaction: http://code.google.com/events/io/2009/sessions/DesignDistributedTransactionLayerAppEngine.html http://blog.notdot.net/2009/9/Distributed-Transactions-on-App-Engine
2010/1/15 Scott Southworth <[email protected]>: > I need to be able to make transaction safe changes across the data at some > times... > Theoretically using any small combination of entities within the group. > > On Thu, Jan 14, 2010 at 4:41 PM, djidjadji <[email protected]> wrote: >> >> Why do these small entities need to be a child of the Main entity? >> What do you gain with the parent-child relation? >> If none, then don't use (large) entity groups. >> There is not much storage gain in elimination of an object reference, >> because the key of the child will be larger because it has a parent. >> >> 2010/1/14 Scott Southworth <[email protected]>: >> > The docs only suggest using a 'single user's worth of data'. My current >> > plan >> > would use one entity group per user, but could contain several thousand >> > small (mostly <1kb) entities in each group. >> > >> > Does anyone have any experience or expectation as to how this would >> > affect >> > performance? Note that there should not be any multi-user contention for >> > these entities. >> > >> > Thanks, >> > Scott Southworth >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups >> > "Google App Engine" group. >> > To post to this group, send email to [email protected]. >> > 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. >> > >> > >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Google App Engine" group. >> To post to this group, send email to [email protected]. >> 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. >> >> >> > > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to [email protected]. > 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. > >
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