<div class="gmail_quote">On Wed, Sep 16, 2009 at 1:41 PM, Peter Körner <span dir="ltr"><<a href="mailto:osm-lists@mazdermind.de">osm-lists@mazdermind.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Ian Dees schrieb:<div><div></div><div class="h5"><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Can a way assume that it uses the most recent version of a node until the way is changed? Then, when a way's revision number increments, all of the rev#'s for the nodes that make up that way are saved along with the way's history.<br>
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But this wouldn't solve the problem of "give me all ways that used node #50, v3" as the last time way #10 was updated it only used node #50, v1 and so that's the last information that's saved.<br><font color="#888888">
</font></blockquote><div><br>What's the problem with that? If way 10 did not ever use node 50v3, then it should not be included in the "give me all ways that use node 50v3" call, right?<br><br>(semi-ASCII-art ahead, arm your fixed-width photos)<br>
<br>Here's way 10v1 (numbers are nodes):<br><br><span style="font-family: courier new,monospace;">50v1----51v1----52v2</span><br style="font-family: courier new,monospace;"><br>...and a history table like this:<br><span style="font-family: courier new,monospace;">way_id way_rev node_id node_rev</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">10 1 50 1</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">10 1 51 1</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">10 1 52 2</span><br style="font-family: courier new,monospace;"><br>I come along and move node 52, causing a rev on the way and a rev on the node:<br><br>
<span style="font-family: courier new,monospace;">50v1----51v1----52v3</span><br style="font-family: courier new,monospace;"><br>...and a history table becomes:<br><span style="font-family: courier new,monospace;">way_id way_rev node_id node_rev</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">10 1 50 1</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">10 1 51 1</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">10 1 52 2</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">10 2 50 1</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">10 2 51 1</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">10 2 52 3</span><br style="font-family: courier new,monospace;">
<br>When you want to find all ways that used node 52v3, you would find way 10.<br></div></div>