[OSM-dev] HEADS UP osmosis pgsql schema users Was: psql osmosis simple shema / smallint out of range

[Daniel Silverstone]

On Mon, 2008-11-03 at 09:50 +0000, Andy Allan wrote:
> Should we restrict the maximum number of relations|ways|nodes that can
> be *direct* members of a relation? I don't mind cascading relations,
> but 39000 direct members of a single relation might casue issues too.

Just as a heads-up to anyone reading this who is part of the API 0.6
stuff, remember that SQL is *NOT GOOD* at arbitrary depth relationships.
I.E. tree structures are a very very bad "corner case" of SQL. Better to
have a fixed heirarchy like:

No more than 'N' nodes in a waysegment, no more than 'W' waysegments in
a way, no more than 'N' nodes in a relationsegment, no more than 'R'
relationsegments in a relation.

At least that way, you know that a single SQL query can retrieve as much
or as little of what you're after as you need.

D.

-- 
Daniel Silverstone                         http://www.digital-scurf.org/
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