--- /dev/null
+Style1;POLYGON (( 10 130, 50 190, 110 190, 140 150, 150 80, 100 10, 20 40, 10 130 ), ( 70 40, 100 50, 120 80, 80 110, 50 90, 70 40 ))\r
+Style2;MULTILINESTRING((10 130,50 190,110 190,140 150,150 80,100 10,20 40,10 130),(70 40,100 50,120 80,80 110,50 90,70 40))\r
<refsection>
<title>Examples</title>
+ <informaltable>
+ <tgroup cols="2">
+ <tbody>
+ <row>
+ <entry><para><informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="images/st_boundary01.png" />
+ </imageobject>
+ <caption><para>Linestring with boundary points overlaid</para></caption>
+ </mediaobject>
+ </informalfigure>
+ <programlisting>SELECT ST_Boundary(geom)
+FROM (SELECT 'LINESTRING(100 150,50 60, 70 80, 160 170)'::geometry As geom) As f;
+ </programlisting>
+<screen>-- ST_AsText output
+MULTIPOINT(100 150,160 170)
+</screen>
+ </para></entry>
+
+ <entry><para><informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="images/st_boundary02.png" />
+ </imageobject>
+ <caption><para>polygon holes with boundary multilinestring</para></caption>
+ </mediaobject>
+ </informalfigure>
+ <programlisting>SELECT ST_Boundary(geom)
+FROM (SELECT
+'POLYGON (( 10 130, 50 190, 110 190, 140 150, 150 80, 100 10, 20 40, 10 130 ),
+ ( 70 40, 100 50, 120 80, 80 110, 50 90, 70 40 ))'::geometry As geom) As f;
+ </programlisting>
+<screen>-- ST_AsText output
+MULTILINESTRING((10 130,50 190,110 190,140 150,150 80,100 10,20 40,10 130),
+ (70 40,100 50,120 80,80 110,50 90,70 40))
+</screen>
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </informaltable>
+
<programlisting>SELECT ST_AsText(ST_Boundary(ST_GeomFromText('LINESTRING(1 1,0 0, -1 1)')));
st_astext
-----------
<refsection>
<title>See Also</title>
- <para><xref linkend="ST_ExteriorRing" />, <xref linkend="ST_MakePolygon" /></para>
+ <para><xref linkend="ST_AsText" />, <xref linkend="ST_ExteriorRing" />, <xref linkend="ST_MakePolygon" /></para>
</refsection>
</refentry>