A datastore write op != an entity put/delete. It is actually (entity + |index deltas|).
For example if you have a Kind with 3 indexed properties and 1 composite index the number of write ops to put a new entity would be: 1 entity + 1 kind index + (1 ascending + 1 descending) * 3 indexed properties + 1 composite index value = 9 write ops if you change a single property on an existing entity it will be: 1 entity + (2 ascending changes + 2 descending changes) * 1 indexed property changed + 2 composite index values changed = 7 write ops (the change must remove the old value and add the new value for each index) deleting the entity will cost the same a creating it (9 write ops) It is important to note that these costs have not changed in the new pricing model, they were just obfuscated in the old model in the form of cpu hours. Hope this clears it up. - Alfred On Tue, Sep 6, 2011 at 2:09 PM, Jason Collins <jason.a.coll...@gmail.com>wrote: > Also, not setting indexed=False on your attributes leads to an > unexpectedly high number of datastore writes. Each attribute without > indexed=False will yield two more datastore write operations (asc, > desc), I believe. > > Even still, we're trying to account for the large number of datastore > write ops.... > > j > > On Sep 6, 3:05 pm, Jason Collins <jason.a.coll...@gmail.com> wrote: > > We are seeing a lot more datastore write operations than we can > > account for (375M / day). Still trying to get to the bottom of it > > because it makes for a scary line item on the new sample bills. We > > haven't looked closely at read operations yet because the writes > > dwarfs it. > > > > This blog post outlines some unexpected read statistics: > http://point7.wordpress.com/2011/09/03/the-amazing-story-of-appengine... > > . I think that using offset with your queries (instead of cursors) > > could lead to an inflated number of reads. > > > > Aside, I'm really surprised that datastore reads cost 70% of a write. > > I would have expected perhaps an order of magnitude cheaper. > > > > j > > > > On Sep 6, 7:57 am, Richard Druce <contactd...@gmail.com> wrote: > > > > > > > > > > > > > > > > > With the appengine pricing changes, we've been paying attention to our > > > datastore puts. According to the pricing comparison chart we're making > 2.18 > > > million puts a day. This seems a lot higher than expected. We receive > about > > > 0.6 queries per second which means that each request is making about 60 > > > puts!! > > > > > Using the sample code for db profilinghttp:// > code.google.com/appengine/articles/hooks.htmlwemeasured this for a > > > day and the most we counted was ~14,000 which seems more reasonable. > Does > > > anyone have experience with something similar on their site? > > > Thanks, > > > Richard > > -- > 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-appengine@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. > > -- 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-appengine@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.
