Hi, Transaction contention only occurs on entities in the same entity group. An entity group consists of a set of entities with the same parent entity. Since neither of the entities in your example have the same parent entity, no, they will not cause contention if they're updated at the same time.
-Nick Johnson On Thu, Apr 7, 2011 at 10:39 AM, Movesax <[email protected]> wrote: > Hello, > > I'm not sure I understand something about transaction contention. Does > contention occur when two people try to update a single instance of a kind > or does contention occur when two people try to update ANY instance of a > kind. I'm not a computer scientist by trade, so to be sure that I have the > terminology correct, if I have the following code: > > class MyEntity() > data = db.SomeProperty() > > > def Main() > A = MyEntity() > B = MyEntity() > > ---------------------------------------- > If two users simultaneously cause: > A.put() and B.put() > to be called. > > does that cause a write contention? > > Thank for any clarification! > > -- > 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. > -- Nick Johnson, Developer Programs Engineer, App Engine -- 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.
