[OSM-dev] API 0.6: Changeset Access

[80n]

On Thu, Jan 29, 2009 at 1:06 AM, Matt Amos <zerebubuth at gmail.com> wrote:

> On 1/28/09, Brett Henderson <brett at bretth.com> wrote:
> > Is the bounding box info updated within the same transaction as entity
> > updates or can it be updated asynchronously with a separate daemon?  I
> > remember discussions about bbox updates only occurring occasionally (ie.
> > the bbox is made slightly larger than necessary to avoid large numbers
> > of writes) but I'm fairly sure they're updated synchronous at the same
> > time as the entity causing the update, at least I hope so.
>
> bounding box info is updated in the same transaction as the entity. as
> you say, the bbox is over-expanded to avoid having to write each time.
> but, because of the restrictions on the member count, the changeset
> ends up needing to be updated every time anyway, rendering the
> previous optimisation pointless :-)
>
> the existing implementation is deliberately naive, which could hurt
> the performance of diff uploads, but there is scope for optimisation
> later on without changing the API.
>

Can someone remind me again please.  What's the purpose of calculating and
storing the bbox for each changeset?



>
> cheers,
>
> matt
>
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