Added estimated_extent() doc.

git-svn-id: http://svn.osgeo.org/postgis/trunk@1130 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/postgis.xml b/doc/postgis.xml
index 625175e4fb51c87ca5e6d3ee5fe48ac0c2676b68..8153822d79cccbf41113b9254a0456be7745c5bd 100644 (file)
--- a/doc/postgis.xml
+++ b/doc/postgis.xml
@@ -3849,6 +3849,20 @@ FROM geometry_table;</literallayout>
           </listitem>
         </varlistentry>
 
+        <varlistentry>
+          <term>estimated_extent(schema, table, geocolumn)</term>
+
+          <listitem>
+            <para>
+           Return the 'estimated' extent of the given spatial table.
+           The estimated is taken from the geometry column's statistics
+           gathered by running VACUUM ANALYZE, and is statistically 
+           about 95% of 'real' extent.
+            </para>
+            <para>NOTE: This is only available with PostgreSQL >= 8.0.0</para>
+          </listitem>
+        </varlistentry>
+
         <varlistentry>
           <term>find_srid(varchar,varchar,varchar)</term>