SDO_INTERSECTION

Question

Here are 3 Examples with the function
SDO_GEOM.SDO_INTERSECTION and unexpected results
Can anybody explain the unexpected results?
Did anybody find similar problems?
Environment:
Server: Windows 2000 Server, Oracle Enterprise Edition 9.2.0.1
Client: Windows 2000 Professional, Oracle Client 9.2.0.1
There are two polagon tables
- DKM_KG with 52 large polygons
- DKM_N_AREA with more tahn 200000 small polygons
Normally the small polygons are "inside or coveredby" the large polygons.
Due to data capture errors some small polygons cross the boundaries of the large polygons.
About 4000 small polygons are incorrect.
We want to find out how much of the area of a small polygon is "outside".
1.EXAMPLE
SQL> select diminfo from user_sdo_geom_metadata where table_name='DKM_N_AREA' ;
DIMINFO(SDO_DIMNAME, SDO_LB, SDO_UB, SDO_TOLERANCE)
SDO_DIM_ARRAY(SDO_DIM_ELEMENT('X', -70000, 20000, .000001), SDO_DIM_ELEMENT('Y',
185000, 275000, .000001), SDO_DIM_ELEMENT('Z', 0, 4000, .000001))
SQL> select diminfo from user_sdo_geom_metadata where table_name='DKM_KG' ;
DIMINFO(SDO_DIMNAME, SDO_LB, SDO_UB, SDO_TOLERANCE)
SDO_DIM_ARRAY(SDO_DIM_ELEMENT('X', -70000, 20000, .000001), SDO_DIM_ELEMENT('Y',
185000, 275000, .000001), SDO_DIM_ELEMENT('Z', 0, 4000, .000001))
SQL> select sdo_geom.validate_geometry_with_context(sdo_geometry,diminfo)
2 from dkm_n_area,
3 user_sdo_geom_metadata
4 where id=87324 and table_name='DKM_N_AREA';
SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT(SDO_GEOMETRY,DIMINFO)
TRUE
SQL> select sdo_geom.validate_geometry_with_context(sdo_geometry,diminfo)
2 from dkm_kg,
3 user_sdo_geom_metadata
4 where kgnr =91109 and table_name='DKM_KG';
SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT(SDO_GEOMETRY,DIMINFO)
TRUE
SQL>
SQL> select sdo_geom.sdo_intersection(a.sdo_geometry,ma.diminfo, b.sdo_geometry,mb.diminfo)
2 from dkm_kg b,dkm_n_area a, user_sdo_geom_metadata mb,
3 user_sdo_geom_metadata ma
4 where
5 mb.table_name='DKM_KG'and ma.table_name='DKM_N_AREA' and
6      b.kgnr =91109 and a.id=87324;
SDO_GEOM.SDO_INTERSECTION(A.SDO_GEOMETRY,MA.DIMINFO,B.SDO_GEOMETRY,MB.DIMINFO)(S
SDO_GEOMETRY(3005, 1028000, NULL, SDO_ELEM_INFO_ARRAY(1, 1, 3), SDO_ORDINATE_ARR
AY(-58141.667, 262670.685, 0, -54724.99, 259343.861, 0, -54712.201, 259324.771,
0))
3 points for the intersection????
SQL> select sdo_geom.sdo_area(sdo_geom.sdo_intersection(a.sdo_geometry,ma.diminfo,
2 b.sdo_geometry,mb.diminfo),0.0001)
3 from dkm_kg b,dkm_n_area a, user_sdo_geom_metadata mb,
4 user_sdo_geom_metadata ma
5 where
6 mb.table_name='DKM_KG'and ma.table_name='DKM_N_AREA' and
7 b.kgnr =91109 and a.id=87324;
SDO_GEOM.SDO_AREA(SDO_GEOM.SDO_INTERSECTION(A.SDO_GEOMETRY,MA.DIMINFO,B.SDO_GEOM
0
NO AREA ????
But with other parameters we get the desired and expected result:
SQL> select sdo_geom.sdo_area(sdo_geom.sdo_intersection(a.sdo_geometry,
2 b.sdo_geometry,0.000000001),0.00001)
3 from dkm_kg b,dkm_n_area a
4 where b.kgnr =91109 and a.id=87324;
SDO_GEOM.SDO_AREA(SDO_GEOM.SDO_INTERSECTION(A.SDO_GEOMETRY,B.SDO_GEOMETRY,0.0000
469693.356
This is the expected result - there are more than 2000 coordinate values
2.EXAMPLE
Another exapmple with unexpected effects:
SELECT sdo_geom.sdo_area(sdo_geom.sdo_intersection(a.sdo_geometry, b.sdo_geometry,
0.000000001),0.000001)
FROM dkm_kg b, dkm_n_area a
WHERE b.kgnr = 90109
AND a.id = 326208;
SDO_GEOM.SDO_AREA(SDO_GEOM.SDO_INTERSECTION(A.SDO_GEOMETRY,B.SDO_GEOMETRY,0.0000
1572512.2
Now the same intersection with another tolerance:
SELECT sdo_geom.sdo_intersection(a.sdo_geometry, b.sdo_geometry, 1)
FROM dkm_kg b, dkm_n_area a
WHERE b.kgnr = 90109
AND a.id = 326208;
There ist no result.
The oracle process needs 100% of the Server CPU and after 10 hours there is no result.
The session is killed:
alter system kill session '9,2064';
The session is marked as killed, but the oracle process still needs 100% CPU.
The instance is shut down, the oracle process still needs 100% CPU, onls a 100KB memory less are needed.
The oracle service has to be stopped (stop process) to release the CPU.
3.EXAMPLE
A third example with strange results
( all geometries are valid!)
select sdo_geom.sdo_intersection(a.sdo_geometry, ad.diminfo,
b.sdo_geometry, bd.diminfo)
from dkm_n_area a, user_sdo_geom_metadata ad,
dkm_kg b, user_sdo_geom_metadata bd
where a.id=261510 and b.kgnr=90013 and
ad.table_name='DKM_N_AREA' and bd.table_name='DKM_KG';
FEHLER in Zeile 2:
ORA-03113: End of Communication!!
A CORE.LOG is produced like
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
Process Id: 0x00000998 Thread Id : 0x00000c54 Time : Fri Sep 12 18:12:38
Excp. Code: 0xc0000005 Excp. Type: ACCESS_VIO Flags: 0x00000000
------------------- Registers ----------------------------
eip = 014bbc29 esp = 05e3a8bc ebp = 05e3ab10 edi = 06a37840 esi = 05e3aad0
eax = 00004020 ebx = 00000000 ecx = 06a37820 edx = 00000000
ecs = 0000001b eds = 00000023 ees = 00000023 ess = 00000023
egs = 00000000 efs = 0000003b
The same query with other tolerances
SQL> select sdo_geom.sdo_intersection(a.sdo_geometry,
2 b.sdo_geometry,0.001)
3 from dkm_n_area a,
4 dkm_kg b
5 where a.id=261510 and b.kgnr=90013;
SDO_GEOM.SDO_INTERSECTION(A.SDO_GEOMETRY,B.SDO_GEOMETRY,0.001)(SDO_GTYPE, SDO_SR
SDO_GEOMETRY(3002, 1028000, NULL, SDO_ELEM_INFO_ARRAY(1, 2, 1), SDO_ORDINATE_ARR
AY(-51608.15, 229893.21, 0, -51606.55, 229890.721, 0))
and
SQL> select sdo_geom.sdo_intersection(a.sdo_geometry,
2 b.sdo_geometry,1)
3 from dkm_n_area a,
4 dkm_kg b
5 where a.id=261510 and b.kgnr=90013;
SDO_GEOM.SDO_INTERSECTION(A.SDO_GEOMETRY,B.SDO_GEOMETRY,1)(SDO_GTYPE, SDO_SRID,
NULL-Result!

Answer 1

After the installation of 9.2.0.4 patch all works well.
A hint for spatial-users with user-defined entries in
MDSYS.CS_SRS table:
Any user-added records are lost during the upgrade.
Save any user defined records in MDSYS tables before applying this patch.