Opened 13 years ago

Last modified 5 years ago

#17 reopened enhancement

adding option to only get "newer than" - objects

Reported by: steve@… Owned by: steve@…
Priority: minor Milestone: OSM 0.7
Component: api Version:
Keywords: Cc:

Description

An option to grab only those objects that are newer than a specific time would enable clients to cache data performantly.

"newer than" must return all objects that changed since the given time, so a last changed timestamp are needed for every object.

Either, the referencing objects of all changed objects are transfered as well. Then this option is nice as stand alone for viewing only recent changes.

Or it really only transfer those objects that have changed, in which case the performance is optimal for clients using caches.

Note, that for the second option, this cannot be done correctly with GPX, e.g. it must be possible to transfer line segments without tracks or property-keys without any object. When using the second option with the XML scheme proposed in the wiki, it has to be allowed, that objects are transfered without their referencing object before (the clause "There must be no reference to an id, which has not been transfered yet." is disabled)

Change History (7)

comment:1 Changed 13 years ago by Tom

Type: defectenhancement

comment:2 Changed 13 years ago by Immanuel Scholz

Either, the referencing objects of all changed objects are transfered as well. Then this option is nice as stand alone for viewing only recent changes.

Or it really only transfer those objects that have changed, in which case the performance is optimal for clients using caches.

The second option is much more important. In fact, I think the former isn't necessary anyway if things like the planet.osm snapshot make the round..

comment:3 Changed 12 years ago by writetodan@…

for this to work, need to have sequential change IDs, as objects can share the same timestamp - i.e. need a version table (as there already is for ways).

comment:4 Changed 12 years ago by Tom Hughes

See also #94 which asks for the same thing.

comment:5 Changed 7 years ago by Richard

Resolution: fixed
Status: newclosed

Five years later, we have minutely diffs!

comment:6 Changed 7 years ago by woodpeck

Priority: majorminor
Resolution: fixed
Status: closedreopened

Minutely diffs do not fix this particular issue.

comment:7 Changed 5 years ago by iandees

Milestone: OSM 0.5OSM 0.7

A newer-than arg to the map call might be interesting to help cut down on data transfer for clients.

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