[OSM-dev] 0.6 - older trackpoints /was: Re: 0.6

Stefan Baebler stefan.baebler at gmail.com
Wed May 7 21:50:32 BST 2008

Dirk-Lüder Kreie wrote:
>>>  > I propose to introduce the ability to limit the age of trackpoints
>>>  > downloaded into the client by introducing an extra parameter "age",
>>>  > eg:
>>>  >
>>>  > GET /api/0.6/trackpoints?bbox=left,bottom,right,top&age=ageInDays&page=pageNumber
>>>  +1! Although it might be easier on the database if the age is
>>>  replaced by a cutoffdate instead?
> Can we fix this to whole days, and make it use the calendar day, instead
> of the last 24 hour period? Otherwise you might get to know which track
> was created exactly when by repeatedly downloading an area and watching
> the differences
As said the time would be the time when the trace was imported into the 
db, so this wouldn't give out personal moving patterns, but time of  
upload patterns (delayed by the time gpx spends in the queue), which 
isn't such an issue i believe. Think of a situation when someone uploads 
7 month old traces and users choose to see only the last 6 months worth 
of traces. Such traces would still be visible for 6 months after being 
uploaded to allow some time for them to be traced.

But it makes sense that such precision (with decimals) is not needed.
Whole days is good enough, heck, the age unit could also be weeks or 
even months to further lower the precision to provide some more 
obfuscation for traces that might not be public (linked to user and 
downloadable as raw gpx), but i don't think this level of additional 
privacy would be necesarry. Midnight (GMT?) seems ok for a cutoff step 
(in case of weeks it would need to be a fixed day of week and in case of 
month a fixed day in month, which could be strange to get used to)


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