[osmosis-dev] one node ways

[Kirill Bestoujev]

Sure, I know this. But if I create an indes with, for example, a st_within
condition, than osmosis falls already while replicating diffs...

That's why I want to solve the problem in osmosis itself, not in the db.

Yesterday on Russian irc channel we found a solution to add to NodeDao.java
linesting update sql-command the following line:

and (select count(1) from (select n.geom as geom, count(1) as node_count
from way_nodes wn join nodes n on n.id = wn.node_id where wn.way_id =
w.idgroup by 1) n_group) > 1

This solves the problem with ways having only duplicate nodes in them.

But the recompiled version of osmosis falls on the following command:

org.springframework.jdbc.
UncategorizedSQLException: PreparedStatementCallback; uncategorized
SQLException for SQL [UPDATE ways w SET linestring = ( SELECT
MakeLine(c.geom) AS way_line FROM ( SELECT n.geom AS geom FROM nodes n INNER
JOIN way_nodes wn ON n.id = wn.node_id WHERE (wn.way_id = w.id) and
array_length(nodes, 1) > 1 ORDER BY wn.sequence_id ) c ) WHERE w.id  = ?];
SQL state [XX000]; error code [0]; ERROR: Exception in LWGEOM2GEOS; nested
exception is org.postgresql.util.PSQLException: ERROR: Exception in
LWGEOM2GEOS

the added code - and array_length(nodes, 1) > 1 - which I thought was
solving the problem does not work OR there is an other problem - not one
node ways.

Kirill


2011/4/9 Jochen Topf <jochen at remote.org>

> Hi!
>
> This has worked for me: I use the ST_isvalid() function in Postgis to find
> out
> if a geometry is valid. If not, I either delete the way or set the geometry
> to
> NULL and then do all further processing only on ways with geometry != NULL.
>
> Jochen
>
> On Fri, Apr 08, 2011 at 08:55:43PM +0400, Kirill Bestoujev wrote:
> > Date: Fri, 8 Apr 2011 20:55:43 +0400
> > From: Kirill Bestoujev <bestoujev at gmail.com>
> > To: Igor Podolskiy <igor.podolskiy at vwi-stuttgart.de>
> > Cc: osmosis-dev <osmosis-dev at openstreetmap.org>
> > Subject: Re: [osmosis-dev] one node ways
> >
> > Igor,
> >
> > the context is simple - we have a mirror of the planet, we update if with
> > replication with minute diffs.
> >
> > You may have a look at way 35966868 to see the problem by yourself. After
> > creation of geom by osmosis it looks like LINESTRING(2.2321042
> > 48.7767191,2.2321042 48.7767191) which is not good.
> >
> >
> >
> > K.
> >
> > 2011/4/8 Igor Podolskiy <igor.podolskiy at vwi-stuttgart.de>
> >
> > > Hi Kirill,
> > >
> > >
> > >  When a one node way is present in the database and osmosis creates a
> > >> linestring geometry for it the resulting geometry is something like
> > >> LINESTRING(139.386972 37.095865)
> > >>
> > >> When we process this linestring with any postgis function it gives us
> > >> an error - the linestring must contain 0 or > 1 nodes.
> > >>
> > >
> > > I think I understand the problem but I'm having a hard time
> understanding
> > > the context :) Could you maybe provide a simple example and/or a
> > > step-by-step guide to reproduce this? Like the osmosis command line
> you're
> > > using, the kind of data you're trying to put in the database - that
> would be
> > > very helpful.
> > >
> > > Regards
> > > Igor
> > >
>
> > _______________________________________________
> > osmosis-dev mailing list
> > osmosis-dev at openstreetmap.org
> > http://lists.openstreetmap.org/listinfo/osmosis-dev
>
>
> --
> Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/ +49-721-388298
>
>
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