[postgis-users] Problem with Buffer function

[Michael de Armas (Micotan)]

I'm trying to calculate a buffer for some geometries, but as I go further 
(increasing the distance) it takes more time until it crashes and kills 
every connection to PostgreSQL when that happens.

For  example, the statement below:

SELECT astext(buffer(transform(GeomFromText('POLYGON((...))', 4267),
                                   32039),
                          20000));

it takes between 5 minutes and 10 minutes, depending on the server workload, 
I guess; when it should take a couple of seconds.

The POLYGON is the WKT for the County of Houston in the State of Texas in 
USA (NAD27). In that statement I'm applying a buffer of 20000 feet, but if I 
try to calculate a buffer of 10 km (32,808 feet) it crashes.

I have found that it happens with geomtries whose boundaries are a bit 
complex (like rivers), but that shouldn't cause such a problem.
(Applying the same buffer on the same geometries with ArcGIS it takes only 
one second)

We just updated to the latest versions of PostGIS and GEOS (POSTGIS="1.1.3" 
GEOS="2.2.3-CAPI-1.1.1" PROJ="Rel. 4.4.9, 29 Oct 2004" USE_STATS), but it 
didn't help.

Any ideas?

Thanks,

Michael.