Quick question -- just for my clarity, and I am sorry if this was already
clear. Once this change is implemented in production (this is not an SDK
question), if prior to writing an new entity, I get one entity id value
using allocate_ids(), is this going to be an integer value of reasonable
size consistent with today's automatically generated IDs? Or will
allocate_ids('mymodel', 1) yield one of the new "bigint" scattered number
IDs? TIA -stevep
On Tuesday, March 26, 2013 6:11:38 PM UTC-7, Jeff Schnitzer wrote:
>
> Will there be any problems intermingling allocated and automatic ids?
> Right now I can switch back and forth between explicitly allocated and
> automatically generated ids. Will this continue to be the case?
>
> Will there be an allocator method to generate a scattered id?
>
> Jeff
>
> On Tue, Mar 26, 2013 at 7:33 PM, Jesse Rohwer
> <roh...@google.com<javascript:>>
> wrote:
> > Hi all,
> >
> > To address the questions on this thread in order:
> >
> > 1. While we will be moving to scattered ids in production soon, we're
> going
> > to limit the size of ids to the max integer that a 64-bit float can
> > represent exactly, which will address the problem with floating-point
> > representations. This will also be changed in the 1.7.7 SDKs.
> >
> > The motivation for scattered ids is that sequential ids cause hot spots
> in
> > bigtable and GAE MR, which leads to significant performance limitations.
> >
> > More info on scattered ids:
> > Scattered auto ids in 1.7.5 SDK
> > See the section "Specifying the automatic id allocation policy":
> >
> https://developers.google.com/appengine/docs/Python/tools/devserver#Using_the_Datastore
>
> >
> https://developers.google.com/appengine/docs/java/tools/devserver#Using_the_Datastore
>
> >
> > 2. The current allocate_ids() functions will continue to allocate
> sequential
> > ids. So, manually allocated sequential ids will still be available.
> >
> > 3. We're sorry for the inconvenience this caused with the 1.7.6 dev
> > appserver, but we're glad we caught this early!
> >
> > 4. If you need small ids, you won't be able to rely on automatic ids for
> > this. One option would be to use the allocate_ids() functions to
> manually
> > allocate ids.
> >
> > Thanks for your feedback!
> >
> > On Monday, March 25, 2013 12:13:52 PM UTC-7, Mahron wrote:
> >>
> >> Ok, so strings it is. Upgrade complete !
> >
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