i too am facing a similar problem, was thinking of a design similar to yours. anyone have any comments on Chris' design?
On Nov 5, 5:35 pm, Chris <cskjoldb...@gmail.com> wrote: > Hi All > > I'm looking for some input onDb.Modeldesign for the following > scenario: > > 1) A User can send a message which will to anywhere between 1 to 5000 > receipients with 200-2000 receipients being by far the the most > common. > 2) Each recipient is expected to receive between 1 and 50 messages a > day. > 3) When a receipent has read a message it needs to be flagged as read. > > For the distribtion of messages to receipients I took inspiration from > thishttp://www.youtube.com/watch?v=AgaL6NGpkB8 > (About 16 minutes into the video) he suggests amodellike this: > > class Message(db.Model): > sender=db.StringProperty() > body=db.TextProperty() > > class MessageIndex(db.Model): > recipient =db.StringListProperty() > > with Message and MessageIndex being in the same entity group. In short > the benefit to this design is supposedly that I can do a key only > query on > the MessageIndex for a particular user. From the MessageIndex keys > returned for the recepient I can extract the actual Message entity > keys and fetch those directly by key. > > That's all well and good...but then I get to 3)...recipients needing > to flag messages as read. For that I'm contemplating something like > this: > > class MessageReadIndex(db.Model): > recipient=db.StringProperty() > month=db.IntegerProperty() > messagesRead =db.StringListProperty(indexed=False) > > When a recipient asks for a list of messages it will be sorted by > date, newest messages first, and paged (think gmail). > In the same page request I can query the MessageReadIndex for the user > and month(s) in question. From here I can loop through each message in > memory and > check to see if it has already been read. > > When the recipient clicks a message to read it I can also retrieve the > MessageReadIndex entity and append the Message Id to the messagesRead > property and put() the entity. > This last bit is what has be a bit worried. It will be quite a few > writes from every recipient every day...again think gmail ;-) Not > indexing the messagesRead > property should help minimize the number of index entries that need > updating ...but still. Am I being overly paranoid and prematurely > optimizing at an unreasonably > level? Does anybody have any better ideas as for how to handle this? > > Thanks in advance for your CPU time! > > /Chris -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appeng...@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
