Hi, Having a version (or even better a timestamp) for last update is also what I use to maintain integrity of my data.
To manage it simply, a) I use a hierarchy of object all inheriting from a DsObject so that I to manage this version only in one place b) I use the @PrePersist annotation (from Objectify) to make it as transparent as possible regards didier On Apr 3, 2:10 pm, Peter Backx <peter.ba...@gmail.com> wrote: > I have an application that accesses a user entity. This entity also contains > a number of user specific settings that the user can update. Some of those > settings are updated by different servlets in parallel (for instance > uploading a profile picture to the blobstore) > > I'm having some serious issues keeping everything in sync. If I'm not > careful, I can easily overwrite updates that have been done in another > thread. > > I have the feeling this is a recurring issue for many GAE application, so > I'm looking for some best practices of how to deal with it. > > In the relational world, often a "version" column is added. Before updating > a row, the version number in the database is compared to the one in memory. > I suppose I can implement something like that on GAE too, but I was > wondering whether there are better/other options available in the NoSQL > world. > > Regards, > Peter -- 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.
