The timestamp would be stored where the root entity is stored, but this is abstracted away from App Engine developers. If this is an area of interest, we can plan an article about how it works underneath the covers. Here's a pretty recent article about how the datastore works:
http://code.google.com/appengine/articles/storage_breakdown.html Not a lot in there about transactions, though, but that would be something we would add to the series. On Wed, Dec 9, 2009 at 5:43 PM, Yasuo Higa <[email protected]> wrote: > Hi Ikai, > > On Thu, Dec 10, 2009 at 2:49 AM, Ikai L (Google) <[email protected]> > wrote: > > Which timestamp are you referring to? > > > I mean timestamp as "committed" timestamp explained by the following > document(50p): > http://snarfed.org/space/datastore_talk.html > > Thanks, > > Yasuo Higa > > > On Tue, Dec 8, 2009 at 6:35 PM, Yasuo Higa <[email protected]> wrote: > >> > >> Thanks for your reply, Ikai. > >> > >> > Entity groups are distributed based on the key and not necessarily the > >> > root > >> > entity. Thus, it is possible to place entities in the same entity > group > >> > without an entity parent. Something similar to what you have done is > >> > also > >> > possible by creating a root entity, adding descendants, then removing > >> > the > >> > root entity. Transactions are possible for entities in the same entity > >> > group. > >> > >> Do you mean that a root key has time-stamp for transaction > >> or an entity group itself is an entity? > >> > >> I would like to know where time-stamp for transaction is stored. > >> > >> Thanks, > >> > >> Yasuo Higa > >> > >> -- > >> > >> 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 > >> [email protected]. > >> To unsubscribe from this group, send email to > >> [email protected]<google-appengine-java%[email protected]> > . > >> For more options, visit this group at > >> http://groups.google.com/group/google-appengine-java?hl=en. > >> > >> > > > > > > > > -- > > Ikai Lan > > Developer Programs Engineer, Google App Engine > > > > -- > > > > 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 > [email protected]. > > To unsubscribe from this group, send email to > > [email protected]<google-appengine-java%[email protected]> > . > > For more options, visit this group at > > http://groups.google.com/group/google-appengine-java?hl=en. > > > > -- > > 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 > [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-appengine-java%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine-java?hl=en. > > > -- Ikai Lan Developer Programs Engineer, Google App Engine -- 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 [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-java?hl=en.
