Point in Polygon/Rectangle problem.

Question

Hi,
I'm want to find out, what points in my DB are inside an user-defined area.
If I have a rectangle and treat it like a rectangle in the query:
SELECT * FROM TABLE WHERE
sdo_relate(point, mdsys.sdo_geometry(2003,8307,null,
mdsys.sdo_elem_info_array(1,1003,3),
mdsys.sdo_ordinate_array(-30,-30, 30,30)),
'mask=INSIDE querytype=window layer_gtype=point') = 'TRUE'
...everything is ok.
If I take the same geometry and use it as an polygon in the query:
SELECT * FROM TABLE WHERE
sdo_relate(point, mdsys.sdo_geometry(2003,8307,null,
mdsys.sdo_elem_info_array(1,1003,1),
mdsys.sdo_ordinate_array(-30,-30, 30,-30, 30,30, -30,30, -30,-30 )),
'mask=INSIDE querytype=window layer_gtype=point') = 'TRUE'
...the result is wrong, there are lots of points that are definitely outside the area. The number of errors is rising the bigger the choosen area becomes.
Any idea?
Best regards
Florian

Answer 1

wateenmooiedag,
this seems to work. Thanks.
But: if I make the query window very large, than again I have wrong results.
Here: http://gdsg.ngdc.noaa.gov/spatial_cookbook.html I found the sentence:
Also, this query will not return the correct number of records if the selection area > one-half the surface of the earth
This is exactly what I'm experienced.
Now I ask myself: how should I use Oracle Spatial if it's not possible to aks for points that are inside a certain polygon (even if the polygon is more than half the world) ??
siva,
I understand what you mean.
But in my case, the problem is not that I get little differences between the rectangle and the polygon. If I use the polygon, I get completely wrong results.
For example: my query window is mdsys.sdo_ordinate_array(-100,-80, 100,-80, 100,80, -100,80, -100,-80 ), than I only get results that are outside the longitude area (-180 to -100 and 100 to 180).
For me this seems to be a bug.
Best regards,
Florian