[postgis-users] What defines a invalid geometry?

[Rhys Ickeringill]

Hi again list,

Apologies for the spammin,. just a quick question this time. The processing
of the query in my previous thread ("Spatial Join Optimisation ") failed
with a GEOS exception. Running...

SELECT uid FROM polygons WHERE NOT isvalid( wkb_geometry )

... results in 275 invalid geometries out of 100,000 or so.

During this query there were lots of NOTICE: statementes regarding "Self
Intersection" and "Ring Self Intersection". Does each of these notices
correspond to a row returned by my select statement?

Thanks,

Rhys