On Sat, May 9, 2009 at 12:25 AM, Ian Dees <[email protected]> wrote: > What is the preferred method of bulk upload nowadays? By bulk, I mean > millions thousands of features with millions of nodes.
probably best to use the diff upload feature. i think ivan has a script for it. more GNIS stuff? > Assuming the preferred pseudocode for upload looks like this: > > open changeset > while more uploads: > upload a diff file > close changeset > > ... how many changes should we put inside of each diff file? How many > uploads should we make in one changeset? the present limit on changeset size is 50,000 edits (i.e: nodes, ways and relations) - so you'll probably need to use more than one changeset, complicating the code a little. you can upload a single diff with all 50,000 changes in it, but that would be huge. its probably better to split it into a number of smaller diffs. > I assume that the capabilities API call will tell me some of this, but I'm > not entirely sure which piece of the capabilities call lines up with which > piece in my example. the only relevant bits are: <waynodes maximum="2000"/> <changesets maximum_elements="50000"/> waynodes maximum is the maximum number of nodes per way - any more and you'll need to split the way. changesets maximum is, well, the maximum number of edits in a changeset. > Is the data written to the database after each diff upload or is it stored > in memory, then written out at the close of a changeset? its written atomically at each diff upload, i.e: each diff upload either succeeds or fails entirely. cheers, matt _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
