SELECT 'buffer', astext(buffer('POINT(0 0)', 1, 2));
SELECT 'geomunion', astext(geomunion('POINT(0 0)', 'POINT(1 1)'));
+SELECT 'unite_garray', astext(unite_garray(geom_accum('{POINT(0 0)}', 'POINT(2 3)')));
SELECT 'convexhull', asewkt(convexhull('POLYGON((0 0, 10 0, 10 10, 0 10, 0 0),(2 2, 2 4, 4 4, 4 2, 2 2))'));
SELECT 'relate', relate('POINT(0 0)', 'LINESTRING(0 0, 1 1)');
SELECT 'relate', relate('POINT(0 0)', 'LINESTRING(0 0, 1 1)', 'F0FFFF*02');
SELECT 'overlaps', overlaps('POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))','POINT(5 5)');
SELECT 'isvalid', isvalid('POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))');
SELECT 'isvalid', isvalid('POLYGON((0 0, 0 10, 10 10, -5 10, 10 0, 0 0))');
+SELECT 'isvalid', isvalid('GEOMETRYCOLLECTION EMPTY');
SELECT 'intersection', astext(intersection('LINESTRING(0 10, 0 -10)', 'LINESTRING(0 0, 1 1)'));
SELECT 'difference', astext(difference('LINESTRING(0 10, 0 -10)', 'LINESTRING(0 2, 0 -2)'));
SELECT 'boundary', astext(boundary('POLYGON((0 0, 0 10, 10 10, 10 0, 0 0),(2 2, 2 4, 4 4, 4 2, 2 2))'));
SELECT 'equals', equals('LINESTRING(0 0, 1 1)', 'LINESTRING(1 1, 0 0)');
SELECT 'pointonsurface', astext(pointonsurface('POLYGON((0 0, 0 10, 10 10, 10 0, 0 0),(2 2, 2 4, 4 4, 4 2, 2 2))'));
SELECT 'centroid', astext(centroid('POLYGON((0 0, 0 10, 10 10, 10 0, 0 0),(2 2, 2 4, 4 4, 4 2, 2 2))'));
+SELECT 'exteriorring', astext(exteriorring(PolygonFromText('POLYGON((52 18,66 23,73 9,48 6,52 18),(59 18,67 18,67 13,59 13,59 18))')));
buffer|POLYGON((1 0,0.707106781202421 -0.707106781170674,4.48965921677393e-11 -1,-0.707106781138927 -0.707106781234168,-1 -8.97931843354786e-11,-0.707106781265914 0.707106781107181,-1.34689776503218e-10 1,0.707106781075434 0.707106781297661,1 0))
geomunion|MULTIPOINT(0 0,1 1)
+unite_garray|MULTIPOINT(2 3,0 0)
convexhull|POLYGON((0 0,0 10,10 10,10 0,0 0))
relate|F0FFFF102
relate|t
contains|t
overlaps|f
isvalid|t
+NOTICE: Self-intersection
isvalid|f
+isvalid|t
intersection|POINT(0 0)
difference|MULTILINESTRING((0 10,0 2),(0 -2,0 -10))
boundary|MULTILINESTRING((0 0,0 10,10 10,10 0,0 0),(2 2,2 4,4 4,4 2,2 2))
equals|t
pointonsurface|POINT(5 5)
centroid|POINT(5.08333333333333 5.08333333333333)
+exteriorring|LINESTRING(52 18,66 23,73 9,48 6,52 18)