[postgis-devel] Fixed precision for ST_Intersection, ST_Union, etc.

[Sandro Santilli]

On Thu, Mar 10, 2016 at 07:47:49AM -0500, Daniel Baston wrote:
> You're right, I didn't describe that well.  I should say instead that these
> functions aren't using GEOS' behavior of cleaning up topological collapses
> (GEOS_PREC_NO_TOPO and GEOS_PREC_KEEP_COLLAPSED in the CAPI).  GEOS is
> indeed doing a pointwise precision reduction, which should be a no-op in my
> use case but may not be in others.

What's the rationale for NOT handling the collapsing ?
Theoretically, feeding invalid geometries to GEOS overlay operations
should result in an exception being thrown or some other undesired
result, so why taking the risk at all ?

--strk;