[OSM-dev] Data corruption :) II

[Matt Amos]

On Wed, Nov 26, 2008 at 7:54 AM, Stefan de Konink <stefan at konink.de> wrote:
> Then let me even get a better proposal; A second machines will be
> installed that has enforced foreign keys. This second machine will produce
> the planet. And will directly trigger events upon corruption so the main
> API doesn't need to cope with them until 0.6.

it is worth noting that foreign keys and transactions alone will
drastically reduce the number of problems, but may not solve them
entirely. the foreign key from current_way_nodes to current_ways and
current_nodes only ensures that those nodes have existed. the
current_* table stores (as the name suggests) the current state of
entities. that state may be "deleted".

what would be ideal is a check like "node_id references
way_nodes.node_id check way_nodes.visible = 1", but i can't find any
documentation for this in mysql or postgres. one solution is to delete
deleted ways/nodes from current_, but this would complicate the code
to determine whether the appropriate response from the API is 403 or
404.

thoughts, suggestions?

cheers,

matt