Error ORA-13364: layer... using /*+ ORDERED */

Question

We develop a spatial application using ORACLE 10.1.0.4 Spatial.
While testing the application we found a very strange behavior:
If we use the /*+ ORDERED */ hint we get an error:
ORA-13364: layer dimensionality does not match geometry dimensions
Here is the query and the results:
SQL> set echo on
SQL> set timing on
SQL> -- omitting "+" this is only a comment
SQL> select /* ORDERED */ GEM.PGNAME from
2 bas.pol_gemeinde GEM, wlk.wb_einzugsgebiet_geo GEO
3 where SDO_ANYINTERACT(gem.geometry,geo.geometry)='TRUE'
4 and GEO.objectid=24481 and geo.geometry is not null and
5 gem.geometry is not null;
PGNAME
Innsbruck
Götzens
Mutters
Elapsed: 00:00:00.07
SQL>
SQL> select /*+ ORDERED */ GEM.PGNAME from
2 bas.pol_gemeinde GEM, wlk.wb_einzugsgebiet_geo GEO
3 where SDO_ANYINTERACT(gem.geometry,geo.geometry)='TRUE'
4 and GEO.objectid=24481 and geo.geometry is not null and
5 gem.geometry is not null;
select /*+ ORDERED */ GEM.PGNAME from
ERROR at line 1:
ORA-13364: layer dimensionality does not match geometry dimensions
ORA-06512: at "MDSYS.SDO_3GL", line 4
ORA-06512: at "MDSYS.MD2", line 726
ORA-06512: at "MDSYS.SDO_3GL", line 115
ORA-06512: at "MDSYS.SDO_3GL", line 142
Elapsed: 00:00:00.04
SQL>
SQL> select /*+ ORDERED */ GEM.PGNAME from
2 wlk.wb_einzugsgebiet_geo GEO , bas.pol_gemeinde GEM
3 where SDO_ANYINTERACT(gem.geometry,geo.geometry)='TRUE'
4 and GEO.objectid=24481 and geo.geometry is not null and
5 gem.geometry is not null;
PGNAME
Innsbruck
Götzens
Mutters
Elapsed: 00:00:00.12
SQL>
The geometry-fields of both tables were checked by sdo_geom.validate_geometry_with_context. There were no errors.
We tested these queries with 10.2.0.1 and got no error.

Answer 1

Hi,
Some spatial operators have function-based implementations, so if the Oracle optimizer decides not to use the spatial index, the operator can complete successfully using the function-based implementation (which is usually very slow).
In this case, because of the order of the tables in the from clause (reverse of what they should be), you've told Oracle not to use the spatial index, and since there is a function-based implementation, Oracle will use it.
It looks like the function-based implementation won't let you join a 3d geometry with a 2d geometry.