[postgis-users] help needed with GEOS & other errors on postgis query

[strk at refractions.net]

There might be a memory leak in the length function.
What PostGIS version are you using ?
--strk;

On Mon, Feb 21, 2005 at 08:17:47PM -0800, Brent Wood wrote:
> 
> I'm using (or trying to use) PostGIS to work with some Antarctic data.
> 
> I have a table with toothfish vessel's set positions, stored as linestrings.
> The set data is lat/long, I loaded it with SRID=4326, then created another
> table with a "create table as select .... transform(the_geom, 20001) from....
> ;"
> 
> I manually added a geometry_columns entry, a spatial index & a date index.
> 
> A second table has all the sea ice density data from the NATICE centre (NOAA)
> as multipolygons.
> 
> The NATICE data is using a custom polar projection (SRID = 20001 in my
> spatial_ref_sys table). The data were downloaded as e00 files, one per week
> since 1977, and were converted using a script via avcimport/ogr2ogr/shp2pgsql. 
> 
> All the shapefiles are loaded into a single table, with a date field as an
> identifier.
> 
> 
> 
> I manually added a geometry_columns entry and created a spatial index & a date
> index.
> 
> I can select & query the data fine, no issues with PostGIS. I can display both
> tables overlayed as I'd expect with QGIS.
> 
> 
> What I want to do is generate a list of sets, where each output record has the
> sea ice (ct) value for the sea ice polygons which cover the same week &
> location as the set, (and the set length) 
> 
> 
> The query I'm trying to run is:
> 
> psql $DB -c "select distinct id,
>                     haul_id,
>                     length(s.the_geom) as set_lgth,
>                     ct
>              from $ICE i,
>                   $SET s
>              where _date >= set_date - interval '3 days'
>                and _date <= set_date + interval '3 days'
>                and s.the_geom && i.the_geom
>                and intersects(s.the_geom, i.the_geom);"
> 
> 
> The result is a GEOS error message:
> 
> NOTICE:  TopologyException: side location conflict (-12.4841,1.2337e+06)
> ERROR:  GEOS overlaps() threw an error!
> 
> I get the same result using intersects instead of overlaps.
> 
> Trying the same query without the last line (no GEOS), it exits with a
> different error:
> 
> ERROR:  out of memory
> DETAIL:  Failed on request of size 32.
> 
> There are 4558 set records and 73225 sea ice polygons. The system is a Linux,
> dual Xeon 2400 with 2.5Gb memory. I'm not convinced there is a genuine memory
> shortage. 
> 
> 
> 
> Any suggestions on how I can try to resolve this?
> 
> 
> Thanks,
> 
>   Brent Wood
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