[postgis-users] geomunion revisited....

[Lee Keel]

Well the good news is that I finally got a configuration that wasn't crying
about memory nor getting the other error....

However, I am back to a much more general question.  Have there been any
improvements to the geomunion() algorithm in versions after 1.2.1?  I have
gotten my buffered polygons for all my linestrings and that part of the
query returns 32,278 rows in about 22 seconds.  But the geomunion of these
rows has been running for over 5 hours.  My problem is that a person can do
this in ArcMap in about 20 minutes.

So the query that takes 22 seconds is:
select simplify(buffer(simplify(the_geom, 5), 400), 150) as the_geom from
table1
union 
select simplify(buffer(simplify(the_geom, 5), 400), 150) as the_geom from
table2


by adding geomunion() to the resulting geometry, it is still running:
select geomunion(the_geom) as the_geom from (
select simplify(buffer(simplify(the_geom, 5), 400), 150) as the_geom from
table1 
union 
select simplify(buffer(simplify(the_geom, 5), 400), 150) as the_geom from
table2) foo


Yes, I know that I must be insane to asking for a single multipolygon like
this.  And I am sure it is outside the normal realm of geomunion(), but it
would sure be nice if it would work. :)

Suggestions welcome.

Thanks in advance,
Lee Keel
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