Handy way of systematically fixing polygon geometries with 13349 and other errors

One often processes sdo_geometry data looking for errors with SQL we get errors in the SQL that stop us seeing what the result is.

 select count(*)
   from oracle_test_geometries a
 where a.geometry is not null;
  
 COUNT(*)
 ------------
 70
  
 select substr(sdo_geom.validate_geometry(a.geometry,0.005),1,10) as errCode
   from oracle_test_geometries a
   where a.geometry is not null
  group by substr(sdo_geom.validate_geometry(A.geometry,0.005),1,10);
  
 Error starting at line 1 in command:
 select substr(sdo_geom.validate_geometry(a.geometry,0.005),1,10) as errCode
   from oracle_test_geometries a
  group by substr(sdo_geom.validate_geometry(A.geometry,0.005),1,10)
 Error report:
 SQL Error: ORA-06502: PL/SQL: numeric or value error
 ORA-06512: at "MDSYS.SDO_GEOM", line 125
 ORA-06512: at "MDSYS.SDO_GEOM", line 460
 06502. 00000 -  "PL/SQL: numeric or value error%s"
 *Cause:    
 *Action:

So, how do we find out what is in error? The following bit of anonymous PL/SQL is helpful in this situation.

 set serveroutput on size unlimited
 DECLARE
    v_err varchar2(10);
 BEGIN
    FOR rec IN (SELECT id, geometry FROM ORACLE_TEST_GEOMETRIES) loop
    BEGIN
       v_err := substr(SDO_GEOM.VALIDATE_GEOMETRY(rec.geometry,0.5),1,10); 
       If ( v_err <> 'TRUE' ) Then
         dbms_output.put_line('Geometry with ID - ' || rec.id || ' - validate result is ' || v_err );
       End If;
       EXCEPTION 
          WHEN OTHERS THEN
             dbms_output.put_line('Geometry with ID - ' || rec.id || ' - failed to validate with ' || SQLCODE );
    END;
    END LOOP;
 END;
 /
  
 anonymous block completed
 Geometry with ID - 204 - validate result is 13350
 Geometry with ID - 205 - validate result is 13356
 Geometry with ID - 28 - validate result is 13366
 Geometry with ID - 141 - validate result is 13356
 Geometry with ID - 25 - validate result is 13351
 Geometry with ID - 29 - validate result is 13349
 Geometry with ID - 30 - validate result is 13349
 Geometry with ID - 37 - validate result is 13341
 Geometry with ID - 45 - validate result is NULL
 Geometry with ID - 46 - validate result is 13028
 Geometry with ID - 47 - validate result is 13356
 Geometry with ID - 48 - validate result is 13356
 Geometry with ID - 49 - validate result is 13356
 Geometry with ID - 50 - validate result is 13351
 Geometry with ID - 51 - validate result is 13351
 Geometry with ID - 52 - validate result is 13351
 Geometry with ID - 53 - failed to validate with -6502
 Geometry with ID - 54 - validate result is 13028
 Geometry with ID - 55 - validate result is 13028
 Geometry with ID - 56 - validate result is 13031
 Geometry with ID - 57 - validate result is 13032
 Geometry with ID - 58 - validate result is 13033
 Geometry with ID - 59 - validate result is 13034
 Geometry with ID - 61 - validate result is 13371
 Geometry with ID - 62 - validate result is 13354
 Geometry with ID - 63 - validate result is 13341
 Geometry with ID - 64 - validate result is 13342
 Geometry with ID - 65 - validate result is 13343
 Geometry with ID - 66 - validate result is 13348
 Geometry with ID - 67 - validate result is 13346
 Geometry with ID - 201 - validate result is 13356 
 Geometry with ID - 202 - validate result is 13348
 Geometry with ID - 203 - validate result is 13366

Note the line:

Geometry with ID – 53 – failed to validate with -6502

The geometry associated with it is:

 select geometry
   from oracle_test_geometries a
 where a.id = 53;
  
 GEOMETRY 
 -------------
 MDSYS.SDO_GEOMETRY(NULL,NULL,NULL,NULL,NULL)

Which, patently, blows up validate_geometry(), though it shouldn’t. Because this geometry stopped the original SQL SELECT statement, we must exclude it if our non-PL/SQL SELECT statements are to succeed. One can do so by nominating the id as above:

 where a.id = 53

Or one could do this:

 where a.geometry is not null
   and a.geometry.sdo_gtype is not null;

Now, what if we tried to fix all the geometries in one non PL/SQL based UPDATE statement:

 update oracle_test_geometries a
    set a.geometry = sdo_util.rectify_geometry(a.geometry,0.005)
 where a.geometry is not null
   and a.geometry.sdo_gtype is not null;
   
 Error starting at line 1 in command:
 update oracle_test_geometries a
    set a.geometry = sdo_util.rectify_geometry(a.geometry,0.005)
 where a.geometry is not null
   and a.geometry.sdo_gtype is not null
 Error report:
 SQL Error: ORA-13199: the given geometry cannot be rectified
 ORA-06512: at "MDSYS.MD", line 1723
 ORA-06512: at "MDSYS.MDERR", line 17
 ORA-06512: at "MDSYS.SDO_UTIL", line 716
 13199. 00000 -  "%s"
 *Cause:    This is an internal error.
 *Action:   Contact Oracle Support Services.

Is it really that bad (ie contact Oracle Support Services)? Maybe. But before you do you need to know which of the many geometries in the table caused:

SQL Error: ORA-13199: the given geometry cannot be rectified

OK, we can fix many of the errors by constructing PL/SQL targeted at fixing specific errors. What follows can be used to fix 13349 (bow-tie in outer boundary of polygon) and 13356 (duplicate vertices):

 set serveroutput on size unlimited
 DECLARE
   v_id oracle_test_geometries.id%type;
   CURSOR c_geometries_to_fix Is
     select id
       from oracle_test_geometries a
      where a.geometry is not null
        and a.geometry.sdo_gtype is not null
        and SDO_GEOM.VALIDATE_GEOMETRY(a.geometry,0.5) IN ('13349','13356')
      for update of geometry;
 BEGIN
    OPEN c_geometries_to_fix;
    LOOP
       FETCH c_geometries_to_fix INTO v_id;
       EXIT WHEN c_geometries_to_fix%NOTFOUND;
       BEGIN
          UPDATE oracle_test_geometries a
             SET a.geometry = sdo_util.rectify_geometry(a.geometry,0.005)
           WHERE CURRENT OF c_geometries_to_fix;
          dbms_output.put_line('RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id ' || v_id);
          EXCEPTION
            WHEN OTHERS THEN
               BEGIN
                   UPDATE oracle_test_geometries a
                      SET a.geometry = sdo_geom.sdo_union(a.geometry,a.geometry,0.005)
                    WHERE CURRENT OF c_geometries_to_fix;
                   dbms_output.put_line('SDO_UNION was successful for oracle_test_geometries geometry with id ' || v_id);
                   EXCEPTION
                     WHEN OTHERS THEN
                          dbms_output.put_line('Could not rectify oracle_test_geometries geometry with id ' || v_id);
               END;
       END;
    END LOOP;
    CLOSE c_geometries_to_fix;
    COMMIT;
 END;
 /
 show errors
  
 anonymous block completed
 RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id 29
 SDO_UNION was successful for oracle_test_geometries geometry with id 30
 RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id 47
 RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id 48
 RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id 49
 RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id 141
 RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id 201
 RECTIFY_GEOMETRY was successful for oracle_test_geometries geometry with id 205

NOTE: You have to have Spatial to execute the SDO_UNION unless you use the one in my GEOPROCESS package.

Of course, what is needed are a set of functions/techniques for fixing other errors,

My TOOLS package includes procedures that can be used to check daily updates and attempt to fix them:

    /*** function    GeometryCheck
    **   description Procedure that processes the supplied object looking
    **                for errors and correcting where possible.
    **                Writes activity to FEATURE_ERRORS table.
    **   param       p_schema      The owner of the table/geometry column data.
    **   param       p_tableName   The table holding the geometry data to be checked.
    **   param       p_ColumnName  The sdo_geometry column in the table to be checked.
    **   param       p_whereClause A predicate to limit the activity to specific rows.
    **/ Procedure GeometryCheck( p_schema IN VarChar2,
                                  p_tableName IN VarChar2,
                                  p_ColumnName IN VarChar2,
                                  p_whereClause IN VarChar2); 

I hope this is helpful to someone.

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