[OSM-dev] Minute Diffs Broken

openstreetmap-dev at scd.debian.net openstreetmap-dev at scd.debian.net
Tue May 5 02:21:06 BST 2009

In article <49FF86A3.8060408 at remote.org> frederik at remote.org wrote:
>Thinking about possible solutions:

>3. Make a semantic change to the way we handle diffs: Let the diff for 
>interval X not be "all changes with timestamp within X" but instead "all 
>changes that happened in a changeset that was closed within X". 
>Changesets not being atomic should pose no problem for this (because 
>when it's closed, it's closed). This would adversely affect downstream 
>systems in that some changes are held back until the changeset is closed 
>(whereas they are passed on immediately now), but on the other hand you 
>could afford to generate the minutely diff at 5 seconds past the minute 
>because you do not have to wait for transactions to settle (the actual 
>changeset close never happens inside a transaction).

Would this work?

How about the situation:

Changeset A creates a node

Changeset B uses the node in a way

Changeset B closes

(Later) Changeset A closes

If the create is delayed until changeset A closes, then B has a way with
an uncreated node.

Trapi depends on all nodes in a way existing to determine what tiles
to place the way in, and all members of a relation to place the
relation in tiles.  (There are some situations where the later isn't
true, so some relations may be missing from some tiles in Trapi.)
Blars Blarson			blarson at scd.debian.net

With Microsoft, failure is not an option.  It is a standard feature.

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