[postgis-devel] CascadedUnion Early Results

[Paul Ramsey]

Looks good so far. Still chasing down an issue with GEOS before I can  
commit, but here's the current results:


uniontest=# select st_area(st_union(the_geom)) from counties where  
state_name = 'Texas';
      st_area
------------------
  65.0596422159988
(1 row)

Time: 702.491 ms

uniontest=# select st_area(st_union_fast(the_geom)) from counties  
where state_name = 'Texas';
      st_area
------------------
  65.0596422159988
(1 row)

Time: 216.526 ms

In the final commit there will just be one st_union() that does the  
right thing. I made two so I could do comparisons like the above more  
easily. Perhaps I should leave in a legacy st_union_slow() for people  
to compare with...

--
Paul Ramsey
OpenGeo - http://opengeo.org
Putting the "Po" in "PostGIS".