ST_DumpPoints(geom, integer[]) is misnamed

[robe]

We should either make this function do something cool or rename it to _ST_DumpPoints.

The user in me was thinking "Why does this function have no description? I wonder if the good PostGIS developers just forgot to document it. I wonder if I can extract the points of an inner ring in a collection of a polygon by doing"

SELECT path, ST_AsText(geom) 
FROM (
  SELECT (ST_DumpPoints(g.geom,ARRAY[4,2])).* 
  FROM
    (SELECT 
       'GEOMETRYCOLLECTION(
          POINT ( 0 1 ), 
          LINESTRING ( 0 3, 3 4 ),
          POLYGON (( 2 0, 2 3, 0 2, 2 0 )),
          POLYGON (( 3 0, 3 3, 6 3, 6 0, 3 0 ), 
                   ( 5 1, 4 2, 5 2, 5 1 )),
          MULTIPOLYGON (
                  (( 0 5, 0 8, 4 8, 4 5, 0 5 ), 
                   ( 1 6, 3 6, 2 7, 1 6 )), 
                  (( 5 4, 5 8, 6 7, 5 4 ))
          )
        )'::geometry AS geom
    ) AS g
  ) AS j;

To my disappointment — ehh you can't - its just a helper function not a navigation function.

[yabo]

Indeed it is, and it was originally named with the '_' prefix, see :

http://trac.osgeo.org/postgis/attachment/ticket/76/my_st_dump_points.2.sql

[kneufeld]

so renamed at r4937