View joining two spatial tables and strange CBO behaviour

Question

Hi all,
I've following view in my database:
CREATE OR REPLACE VIEW my_view AS
SELECT id, 'table1' AS source, location FROM my_table1
UNION ALL
SELECT id, 'table2' AS source, location FROM my_table2;
When I execute query:
SELECT * FROM my_view WHERE SDO_RELATE(location, SDO_GEOMETRY(...), 'mask=anyinteract') = 'TRUE';
It works as expected.
When running query like (getting location with subquery):
SELECT * FROM my_view WHERE SDO_RELATE(location, (SELECT location FROM my_table3 WHERE id = 123, 'mask=anyinteract') = 'TRUE';
It doesn't work. Oracle Throws "DatabaseError: ORA-13226: interface not supported without a spatial index"
Further investigation revealed strange behaviour of CBO:
In first case Oracle CBO uses Spatial index just fine and as expected.
But second query and CBO get's a bit strange - unique index scan is used for subselect, but for view tables is full table scan is used and SDO_RELATE is not happy with that since no spatial index is used.
How I can use spatial indexes regardless of that subselect?

Answer 1

Hi folks,
Looking over these responses and not finding a lot of clarity yet in terms of leaving a trail for future readers to glean an answer from.  I was just looking through the back-and-forth and curious myself about the issue  First of all I think Jani's observations are quite on target.  This CBO reaction is weird and does not work they way most Oracle users would expect it to work.  Secondly, Jani really should tell us his Oracle version and folks providing answers should as well - the CBO is always being tweaked.  Thirdly, Stefan provides a solution though it's a rather expensive solution to my taste.  And finally, I think we as a group need to spend a bit more time reproducing things in code.  I will give it a shot, feel free to correct anything I got wrong.
So first of all, I wrote this up quick on 12.1.0.2 and verified it was the same on 11.2.0.4
DROP TABLE my_table1 PURGE;
CREATE TABLE my_table1(
    objectid INTEGER NOT NULL
   ,tsource  VARCHAR2(30 Char)
   ,shape    MDSYS.SDO_GEOMETRY
   ,PRIMARY KEY(objectid)
DROP TABLE my_table2 PURGE;
CREATE TABLE my_table2(
    objectid INTEGER NOT NULL
   ,tsource  VARCHAR2(30 Char)
   ,shape    MDSYS.SDO_GEOMETRY
   ,PRIMARY KEY(objectid)
DROP TABLE my_table3 PURGE;
CREATE TABLE my_table3(
    objectid INTEGER NOT NULL
   ,tsource  VARCHAR2(30 Char)
   ,shape    MDSYS.SDO_GEOMETRY
   ,PRIMARY KEY(objectid)
CREATE OR REPLACE PROCEDURE seeder(
   p_count IN NUMBER
AS
   sdo_foo MDSYS.SDO_GEOMETRY;
   int_counter NUMBER := 1;
   FUNCTION random_line
   RETURN MDSYS.SDO_GEOMETRY
   AS
      num_x1 NUMBER;
      num_y1 NUMBER;
      num_offx NUMBER;
      num_offy NUMBER;
   BEGIN
      num_x1 := dbms_random.value(-179,179);
      num_y1 := dbms_random.value(-89,89);
      RETURN MDSYS.SDO_GEOMETRY(
          2002
         ,8265
         ,NULL
         ,MDSYS.SDO_ELEM_INFO_ARRAY(1,2,1)
         ,MDSYS.SDO_ORDINATE_ARRAY(
              num_x1
             ,num_y1
             ,num_x1 + 0.0001
             ,num_y1 + 0.0001
   END random_line;
BEGIN
   FOR i IN 1 .. p_count
   LOOP
      sdo_foo := random_line();
      INSERT INTO my_table1
      VALUES (
          int_counter
         ,'table1'
         ,sdo_foo
      int_counter := int_counter + 1;
      sdo_foo := random_line();
      INSERT INTO my_table2
      VALUES (
          int_counter
         ,'table2'
         ,sdo_foo
      int_counter := int_counter + 1;
      sdo_foo := random_line();
      INSERT INTO my_table3
      VALUES (
          int_counter
         ,'table3'
         ,sdo_foo
      int_counter := int_counter + 1;
   END LOOP;
   INSERT INTO my_table1
   VALUES (
       0
      ,'table1'
      ,MDSYS.SDO_GEOMETRY(
           2002
          ,8265
          ,NULL
          ,MDSYS.SDO_ELEM_INFO_ARRAY(1,2,1)
          ,MDSYS.SDO_ORDINATE_ARRAY(
               -87.8211111
              ,42.5847222
              ,-87.8212
              ,42.5848
   INSERT INTO my_table3
   VALUES (
       0
      ,'table3'
      ,MDSYS.SDO_GEOMETRY(
           2002
          ,8265
          ,NULL
          ,MDSYS.SDO_ELEM_INFO_ARRAY(1,2,1)
          ,MDSYS.SDO_ORDINATE_ARRAY(
               -87.8211111
              ,42.5848
              ,-87.8212
              ,42.5847222
   COMMIT;
END seeder;
BEGIN
   seeder(100000);
END;
SELECT 'my_table1: ' || COUNT(*) AS invalid_count FROM my_table1 WHERE MDSYS.SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT(shape,0.05) <> 'TRUE'
UNION ALL
SELECT 'my_table2: ' || COUNT(*) AS invalid_count FROM my_table2 WHERE MDSYS.SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT(shape,0.05) <> 'TRUE'
UNION ALL
SELECT 'my_table3: ' || COUNT(*) AS invalid_count FROM my_table3 WHERE MDSYS.SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT(shape,0.05) <> 'TRUE';
BEGIN
   INSERT INTO user_sdo_geom_metadata(
       table_name
      ,column_name
      ,diminfo
      ,srid
   ) VALUES (
       'MY_TABLE1'
      ,'SHAPE'
      ,MDSYS.SDO_DIM_ARRAY(MDSYS.SDO_DIM_ELEMENT('X',-180,180,.05),MDSYS.SDO_DIM_ELEMENT('Y',-90,90,.05))
      ,8265
   COMMIT;
EXCEPTION
   WHEN OTHERS
   THEN
      NULL;
END;
BEGIN
   INSERT INTO user_sdo_geom_metadata(
       table_name
      ,column_name
      ,diminfo
      ,srid
   ) VALUES (
       'MY_TABLE2'
      ,'SHAPE'
      ,MDSYS.SDO_DIM_ARRAY(MDSYS.SDO_DIM_ELEMENT('X',-180,180,.05),MDSYS.SDO_DIM_ELEMENT('Y',-90,90,.05))
      ,8265
   COMMIT;
EXCEPTION
   WHEN OTHERS
   THEN
      NULL;
END;
BEGIN
   INSERT INTO user_sdo_geom_metadata(
       table_name
      ,column_name
      ,diminfo
      ,srid
   ) VALUES (
       'MY_TABLE3'
      ,'SHAPE'
      ,MDSYS.SDO_DIM_ARRAY(MDSYS.SDO_DIM_ELEMENT('X',-180,180,.05),MDSYS.SDO_DIM_ELEMENT('Y',-90,90,.05))
      ,8265
   COMMIT;
EXCEPTION
   WHEN OTHERS
   THEN
      NULL;
END;
CREATE INDEX my_table1_spx ON my_table1
(shape)
INDEXTYPE IS MDSYS.SPATIAL_INDEX
NOPARALLEL;
CREATE INDEX my_table2_spx ON my_table2
(shape)
INDEXTYPE IS MDSYS.SPATIAL_INDEX
NOPARALLEL;
CREATE INDEX my_table3_spx ON my_table3
(shape)
INDEXTYPE IS MDSYS.SPATIAL_INDEX
NOPARALLEL;
BEGIN
   dbms_stats.gather_table_stats(USER, 'MY_TABLE1');
   dbms_stats.gather_index_stats(USER, 'MY_TABLE1_SPX');
   dbms_stats.gather_table_stats(USER, 'MY_TABLE2');
   dbms_stats.gather_index_stats(USER, 'MY_TABLE2_SPX');
   dbms_stats.gather_table_stats(USER, 'MY_TABLE3');
   dbms_stats.gather_index_stats(USER, 'MY_TABLE3_SPX');
END;
CREATE OR REPLACE VIEW my_view
AS
SELECT
objectid
,'table1' AS tsource
,shape
FROM
my_table1
UNION ALL
SELECT
objectid
,'table2' AS tsource
,shape
FROM my_table2;
set timing on;
-- QUERY #1
-- Jani's original setup, works as expected
SELECT
COUNT(*) AS single_geom_counter
FROM
my_view a
WHERE
MDSYS.SDO_RELATE(
    a.shape
   ,MDSYS.SDO_GEOMETRY(
        2002
       ,8265
       ,NULL
       ,MDSYS.SDO_ELEM_INFO_ARRAY(1,2,1)
       ,MDSYS.SDO_ORDINATE_ARRAY(
            -87.8211111
           ,42.5848
           ,-87.8212
           ,42.5847222
   ,'mask=anyinteract'
) = 'TRUE';
-- QUERY #2
-- Now the problem statement
SELECT
COUNT(*) AS table_problem_counter
FROM
my_view a
WHERE
MDSYS.SDO_RELATE(
    a.shape
   ,(SELECT b.shape FROM my_table3 b WHERE b.objectid = 0)
   ,'mask=anyinteract'
) = 'TRUE';
-- QUERY #3
-- Stefan's solution
SELECT  /*+ ORDERED */
COUNT(*) AS stefans_solution
FROM
my_table3 a
,my_view b
WHERE
a.objectid = 0
AND MDSYS.SDO_RELATE(
    a.shape
   ,b.shape
   ,'mask=anyinteract'
) = 'TRUE';
Anyhow, so the hard coded query #1 that Jani provided works exactly the way most folks would expect, the second item in the relate is applied to each spatial index participating in the view.  I think we can agree this is what we want.
Now when we move on to the problem, well its all goes off the rails as I think its looks to apply the spatial filter to the view itself which lacks an index (not sure really)
So as Stefan says, you can work around this by rewriting things as query #3 does above though now its a full table scan of both tables in the view.  This is a long way performance wise from Query #1!
So on my 12c test box
   query #1 Elapsed: 00:00:00.016
   query #3 Elapsed: 00:00:33.534
On 11g production box
   query #1 Elapsed: 00:00:00.49
   query #3 Elapsed: 00:02:31.45   (ouch!)
So hopefully someone else can jump in with more information on better solutions?  
I overall tend to avoid the kind of unioned views that Jani is using here.  I have a hard time recalling why but I must have been burned similarly many years ago when I was first starting with Oracle spatial.  I tend to always want my spatial indexes right there where I can keep a grim stink eye on them.  It may be that a unioned view with multiple spatial indexes behind it might just be a bad practice better done with a materialized view?  Or maybe a lesser term?  Unprofitable practice?  fraught?  "Best if you don't do that"?
Anyhow, I would be interested in what others have as input on the matter.
Cheers,
Paul