[postgis-devel] chunked GeomUnion commit

[strk at refractions.net]

Bill, sorry but there has been many changes recently in ALL
repositories...

I will now freeze GeomUnion related works in all of them
to take allow you running tests.

Briefly:
	GEOS improvements have been ported from JTS
	and customly made for Buffer op. Generally
	speaking HEAD branch should be faster then
	2.1-branch. 2.1-branch should be *faster* 
	then 2.1.2, if you really see other results
	we have a problem!

	PostGIS GeomUnion function now uses 'chunked'
	buffering of input. Size of chunks is defined
	by number of vertex in input and you can
	set it using a define at top of lwgeom_geos.c.	
	This is both in HEAD and 1.0-branch.
	In both cases using buffer(collect(p),0) would
	use a single BIG chunk thus giving better results
	if available memory is enough.
	Buffer(collect(p),0) would work on all postgis
	*releases*.

When online you can talk to me on freenode irc network.

--strk;