Hey Jeff, those are both good questions. The first I don't honestly know but I'll see if we can figure out an answer for it. The second seems reasonable, I'll chat with Alfred and Max about it.
Greg On Fri, Jun 24, 2011 at 11:04 PM, Jeff Schnitzer <j...@infohazard.org>wrote: > Thanks, this clarifies much! Questions below: > > On Thu, Jun 23, 2011 at 11:49 PM, Gregory D'alesandre <gr...@google.com>wrote: > >> Datastore APIs Q: Which operations are being charged for? >> A: There are 3 categories of Datastore operations: >> - Write operations (Entity Put, Entity Delete, Index Write), each of these >> operations will cost $0.10 per 100k operations >> - Read operations (Query, Entity Fetch), each of these operations will >> cost $0.07 per 100k operations >> - Small operations (Key Fetch, Id Allocation), each of these operations >> will cost $0.01 per 100k operations >> >> Q: Under the new scheme, is it more economical to do a keys-only query >> that fetches 1000 keys, and then do a get on the 500 of them that I need, or >> just do a regular (non keys-only) query for all 1000 directly? >> A: The first is more economical. Fetching 1000 keys + fetching 500 >> entities = $0.0001 + 0.00035 = $0.00045; fetching 1000 entities = $0.0007. >> > > This makes sense, and encourages more use of memcache. to hold entities. > One question that I've been wondering a while - presuming no caching, does > this query-keys+batch-get approach produce higher latency than a simple > query, and if so, by how much? > > Also, is there any way we can get the transaction timestamp out on > datastore writes? This would *dramatically* improve the robustness of code > that tries to keep memcache in sync with the datastore during contention. > I've spoken with Alfred and Max about this, but I don't know if it's a > priority. This could potentially reduce datastore bills by orders of > magnitude. > > Thanks, > Jeff > > -- > 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.
