revise st_union example to show new and faster way of doing multi-band union

git-svn-id: http://svn.osgeo.org/postgis/trunk@10362 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference_raster.xml b/doc/reference_raster.xml
index 0b344c221fa1dd2139cbaff5a34887522c814ba1..d7ec1fb2afb213a538943205a6e204869698fbea 100644 (file)
--- a/doc/reference_raster.xml
+++ b/doc/reference_raster.xml
@@ -8721,6 +8721,7 @@ UPDATE wind
 
                                <para>Availability: 2.0.0 </para>
                                <para>Enhanced: 2.1.0 Improved Speed (fully C-Based).</para>
+                               <para>Changed: 
                        </refsection>
                                
                        <refsection>
@@ -8736,7 +8737,7 @@ FROM sometable WHERE filename IN('dem01', 'dem02') GROUP BY filename;</programli
                                <title>Examples: Return a multi-band raster that is the union of tiles intersecting geometry</title>
                                <programlisting>
 -- this creates a multi band raster collecting all the tiles that intersect a line
-SELECT ST_AddBand(NULL,ARRAY[ST_Union(rast,1), ST_Union(rast,2), ST_Union(rast,3) ])
+SELECT ST_Union(rast,ARRAY[ROW(1, 'LAST'), ROW(2, 'LAST'), ROW(3, 'LAST')]::unionarg[])
 FROM aerials.boston
 WHERE ST_Intersects(rast,  ST_GeomFromText('LINESTRING(230486 887771, 230500 88772)',26986) );</programlisting>
                        </refsection>