Group by GEOM and get unique points

Question

Hello,
I need some help with a spatial query. I have a table of addresses and wanted to know if there is an easy way to group by x and y coordinates , so that I just get one record for multiple addresses with the same coords (and do simple clustering).
This is my current sql statement
select map_id, m.shape.sdo_point.x as X, m.shape.sdo_point.y
from MAPS m
where MDSYS.SDO_RELATE (m.SHAPE,
MDSYS.SDO_GEOMETRY(2003,
8311,
NULL,
MDSYS.SDO_ELEM_INFO_ARRAY(1, 1003, 3),
MDSYS.SDO_ORDINATE_ARRAY(<%= mbrCoords[3]%>, <%= mbrCoords[2]%>, <%= mbrCoords[1]%>, <%= mbrCoords[0]%>)), 'mask=ANYINTERACT') = 'TRUE';

Answer 1

Hi,
another way would be like this (geom is SDO_GEOMETRY)
-- 2D
select A.* from
       select t.id, gv.x,gv.y
       from <TABLE> t, table(sdo_util.getvertices(t.geom)) gv
       ) A, (
       select count (gv.x||gv.y) ct , gv.x,gv.y
       from <TABLE>, table(sdo_util.getvertices(geom)) gv
       group by gv.x,gv.y
       ) B
where A.X = B.X and A.Y = B.Y
and B.ct > 1
-- 3D
select A.* from
       select t.id, gv.x,gv.y ,gv.z
       from <TABLE> t, table(sdo_util.getvertices(t.geom)) gv
       ) A, (
       select count (gv.x||gv.y||gv.z) ct , gv.x,gv.y,gv.z
       from <TABLE>, table(sdo_util.getvertices(geom)) gv
       group by gv.x,gv.y,gv.z
       ) B
where A.X = B.X and A.Y = B.Y and A.Z = B.Z
and B.ct > 1