[postgis-users] Polygon Boundary

[Michael Welter]

Is there a function that, given a set of Tiger line segments, will 
determine a polygon's exterior boundary?  The set includes interior line 
segments.

I'm looking for something similar to ConvexHull() except that it needs 
to handle concave edges as well.

I'm able to perform the function by analyzing vertices and sides, but 
some polygons have interior polygons (i.e. a lake) that touch the 
exterior polygon--this drastically increases the level of complexity.

Is there such a function?

Thanks,
Mike