[postgis-users] more stuff in CVS

[David Blasby]

I've added a bunch of stuff to the CVS version of PostGIS.

Its pretty much OGC SF SQL 
(http://www.opengis.org/techno/specs/99-049.pdf) conformant now.

You can run the ogc test suite ("examples/ogc_test_suite/") and it will 
run with all correct answers.  NOTE: the last tests (convexHull() and 
buffer()) will crash the server - see (b) below.


Here's a current list of issues that need attention before postgis v1.0:

a. more testing - just added and changed a bunch of stuff that need to 
be tested
b. GEOS - there are some bugs in the GEOS CVS version.  Yuri is working 
on them.  This is mostly convexHull() and buffer().
c. GEOS - memory management.  When yuri commits the new GEOS, I'll have 
postgis delete GEOS geometries (currently you cannot).
d. Add full support for postgresql 7.3 schemas
e. PostGIS has some issues with the postgresql 7.4 beta (in the optional 
statistical analysis package)
f. I've added a bunch of documentation, but there still needs to be more
g. better error messages (esp for GEOS stuff)


Other issues regarding conformance
------------ ---------------------
1. postgis GEOMETRYCOLLECTION() cannot have geometrycollection (or 
multi*) sub components.  For example -
GEOMETRYCOLLECTION( LINSTRING(0 0, 1 1), MULTIPOINT(0 0, 1 1))  -->
GEOMETRYCOLLECTION( LINSTRING(0 0, 1 1), POINT(0 0),POINT(1 1) )
This shouldnt really be a big issue for anyone

2. Some of the esoteric WKT geometry variants are not allowed:
LINESTRING(EMPTY)  {use MULTILINESTRING(EMPTY) instead}
POINT(EMPTY)  	   {use MULTIPOINT(EMPTY)      instead}
POLYGON((EMPTY))   {use MULTIPOLYGON(EMPTY)    instead}

3. Since "union" is a reserved SQL word, I'm using "geomunion()" instead

4. GEOS has some "issues" revolving around using geometries of type 
GEOMETRYCOLLECTION. Currently, functions like "intersection(g1,g2)" will 
throw an error if g1 or g2 are GEOMETRYCOLLECTIONS.

I dont expect any of these issues to affect anyone, except #4.  We'll 
probably have a discussion on the JTS/GEOS list regarding this.

dave