Window SRID does not match Layer SRID question

Question

I would like to do a simple window query to see what points fall inside a specific rectangle as follows:
select gm.land
from frame_boundary fb, geometry_map gm
where SDO_RELATE(gm.location,fb.boundary, 'mask=anyinteract
querytype=window') = 'TRUE'
and fb.sessionid = '240' and fb.framenumber = '0' ;
The problem is that the SRIDs do not match. the points in the geometry_map table have an SRID of 8265, while the frames in my frame_boundary table have a null SRID.
My question is this:
Is there an easy way around this problem? ...or do I need to re-input all the points to the geom_map to have null SRIDs so that they both match. - this would be a nightmare!!!
I tried to do an SDO_Filter query instead, this is fine when I put in the 4 coordinates of the frame manually (see below) , but I think the same SRID problem rears its head when I just reference a frame by its id.
SELECT gm.Land
FROM GEOMETRY_MAP gm, FRAME_BOUNDARY fb
WHERE SDO_FILTER(gm.LOCATION,
(MDSYS.SDO_GEOMETRY(2003, 8265, NULL,
MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,1),
MDSYS.SDO_ORDINATE_ARRAY(-104.98628, 39.975784, -104.47771, 39.756035))),
'QUERYTYPE=WINDOW')='TRUE' and fb.sessionid = '240') ;
Any suggestions would be greatly appreciated.
Many thanks,
Eoin.

Answer 1

Eoin,
Per the Oracle Spatial User's Guide and Reference, "For Spatial operators that take two geometries as input parameters, if the geometries are based on different coordinate systems, the query window (the second geometry) is transformed to the coordinate system of the first geometry before the operation is performed. This transformation is a temporary internal operation performed by Spatial; it does not affect any stored query-window geometry." The problem in the first query is not that the SRIDs don't match, it's that in order for coordinate system transformation to work, there must be a SRID for the second geometry (in other words, it cannot be NULL). Your best bet in this case would be to update the frame_boundary table to include a SRID. You can do this by simply dropping the index on frame_boundary, using an update statement (update frame_boundary fb set fb.boundary.sdo_srid=8265), update the USER_SDO_GEOM_METADATA view to include the SRID for frame_boundary, then reindex.
Other things to note here:
1) If frame_boundary truly includes only rectangles, SDO_FILTER will be faster as it will compute an anyinteract calculation based solely on the index (which is an MBR-only calculation that may work almost exactly as SDO_RELATE was working for you).
2) If you are pulling the geometries from two tables, you will want to include an /*+ ORDERED */ optimizer hint. So, your first query would look like this:
select /*+ ORDERED */ gm.land
from frame_boundary fb, geometry_map gm
where SDO_RELATE(gm.location,fb.boundary, 'mask=anyinteract
querytype=window') = 'TRUE'
and fb.sessionid = '240' and fb.framenumber = '0' ;
3) The second query you listed is not working because the "and fb.sessionid = '240'" is followed by an extra parenthesis. That query should look like:
SELECT gm.Land
FROM GEOMETRY_MAP gm, FRAME_BOUNDARY fb
WHERE SDO_FILTER(gm.LOCATION,
(MDSYS.SDO_GEOMETRY(2003, 8265, NULL,
MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,1),
MDSYS.SDO_ORDINATE_ARRAY(-104.98628, 39.975784, -104.47771, 39.756035))),
'QUERYTYPE=WINDOW')='TRUE'
and fb.sessionid = '240' ;
Hope this helps.
-Justin