If you don't its better to do it on the server side rather than transferring data through the net. No you don't need to keep the keys locally.
2009/4/27 Sri <[email protected]> > > But the issue is that i dont really have the keys on me... does that > mean that each time i load the datastore il have to keep track of the > keys as well locally.. so that when i want to clear them i can use > them.. > > cheers > Sri > > On Apr 27, 8:50 am, Alkis Evlogimenos ('Αλκης Ευλογημένος) > <[email protected]> wrote: > > The sample code does: > > MyModel.all().fetch(1000) > > > > This means fetch 1000 entities of MyModel. If each entity is 10kb this > means > > 10MB of data read from datastore, 10MB of data sent through the network > to > > your running instance and 10MB of data server from the running instance > to > > your machine running the remote script. > > > > If you know the keys then you can do: > > > > db.delete([db.Key.from_path('MyModel', key_name) for key_name in > > one_thousand_key_names]) > > > > This just sends the keys to the datastore for deletion. It doesn't need > to > > transfer data from the datastore to the remote script to read the keys in > > the first place. > > > > Eventually GAE api should provide us some way of querying the datastore > for > > keys only instead of getting entities necessarily. This would make this > > use-case quite a bit faster and a lot of others as well. > > > > 2009/4/26 Devel63 <[email protected]> > > > > > > > > > > > > > Can you explain this further? I don't see any reference to key_name > > > in the sample code. > > > > > More importantly, to me, what's the cost differential between using > > > string representation of keys and key_names? I've been passing around > > > key_names to the browser because they're shorter, under the assumption > > > that the cost to get the corresponding key on the server side was > > > negligible. > > > > > On Apr 25, 9:02 am, Alkis Evlogimenos ('Αλκης Ευλογημένος) > > > <[email protected]> wrote: > > > > Doing it over the remote api means you are going to transfer all your > > > data + > > > > transmission overhead over the wire. You are probably better off > doing > > > > something like this on the server side through an admin protected > > > handler. > > > > > > Also if you happen to know the keys of your data (you used key_name) > your > > > > deletes are going to be a lot more efficient if you give db.delete a > list > > > of > > > > keys instead. > > > > > > On Sat, Apr 25, 2009 at 2:41 PM, Sri <[email protected]> wrote: > > > > > > > Hi, > > > > > > > Is there a way to completely erase the production data store? > > > > > > > Currently I am using a script like this via the remote api: > > > > > > > def delete_all_objects(obj_class): > > > > > num_del = 300 > > > > > while True: > > > > > try: > > > > > objs = obj_class.all().fetch(1000) > > > > > num_objs = len(objs) > > > > > if num_objs == 0: > > > > > return > > > > > print "Deleting %d/%d objects of class %s" % (num_del, > > > > > num_objs, str(obj_class)) > > > > > db.delete(objs[:num_del]) > > > > > except Timeout: > > > > > print "Timeout error - continuing ..." > > > > > > > But with 30000 entities in the data store and another 3 million > (yep > > > > > thats right) coming, doing a clear this way is extremely slow. > > > > > > > Any ideas? > > > > > > > cheers > > > > > Sri > > > > > > -- > > > > > > Alkis > > > > -- > > > > Alkis > > > -- Alkis --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
