VERY slow SDO_GEOM.RELATE funcktion call

Question

Hi,
I have the table definition below. The table contains over 3,5 million records. What we experience is that the following query runs terribly slow. With 100 thousand records it takes 14 seconds, with 3,5 million records we can not wait till it executes.
Is the relate function supposed to handle this amount of data? We are using oracle 11g on Windows.
Regards,
Tamas
*======= SLOW RUNNING QUERY ===================*
function FM_SELECT_OG_BY_GEOM_CUR(I_OG mdsys.SDO_GEOMETRY,
I_MASK varchar default G_MASK ,
I_TOLERANCE number default G_TOLERANCE )
return SYS_REFCURSOR is
L_REC_SET SYS_REFCURSOR;
begin
open L_REC_SET for
select OG.AZONOSITO
from OBJEKTUM_GEOMETRIAK OG
where MDSYS.SDO_GEOM.RELATE(OG.OBJEKTUM_GEOMETRIA,
I_MASK,
I_OG,
I_TOLERANCE) != 'FALSE';
return L_REC_SET;
exception
when others then
open L_REC_SET for 'select null AZONOSITO from dual where 1=2 ';
return L_REC_SET;
end;
*======= TABLE DEFINITION ======================*
create table OBJEKTUM_GEOMETRIAK
AZONOSITO number( 10 ),
OBJEKTUM_SZIMBOLIKA number( 10 ) not null,
OBJEKTUM_AZONOSITO number( 10 ) not null,
OBJEKTUM_GEOMETRIA sdo_geometry, -- pontatlan
MAP_ID number( 10 ) not null,
COLOR number( 5 ),
STYLE number( 2 ), -- STYLE
WEIGHT number( 2 ), -- WEIGHT
FONT_ID number( 3 ), -- FONT
WIDTH number( 9,3 ), -- WIDTH
HEIGHT number( 9,3 ), -- HEIGHT
JUSTIFICATION_ID number( 2 ), -- JUSTIFICATION
FELIRAT varchar( 256 ),
FORGATAS number(10,3),
     OBJEKTUM_KOMPONENS number( 10 ) not null
) tablespace MIR_TAB_MST;
alter table OBJEKTUM_GEOMETRIAK add (primary key (AZONOSITO));
create index IDX_OBJEKTUM_GEOMETRIAK_2
on OBJEKTUM_GEOMETRIAK( MAP_ID )
tablespace MIR_IDX_MST;
insert into USER_SDO_GEOM_METADATA
values ( 'OBJEKTUM_GEOMETRIAK',
'OBJEKTUM_GEOMETRIA',
MDSYS.SDO_DIM_ARRAY( MDSYS.SDO_DIM_ELEMENT( 'X',
600000,
900000,
0.001 ), MDSYS.SDO_DIM_ELEMENT( 'Y',
150000,
400000,
0.001 ) ),
null );
create index IDX_OBJEKTUM_GEOMETRIAK_1 on OBJEKTUM_GEOMETRIAK ( OBJEKTUM_GEOMETRIA ) indextype is MDSYS.
SPATIAL_INDEX
parameters(' ') noparallel;
create index IDX_OBJEKTUM_GEOMETRIAK_3
on OBJEKTUM_GEOMETRIAK (OBJEKTUM_AZONOSITO )
tablespace MIR_IDX_MST;

Answer 1

HI,
Just want to add some information between the performance difference between a spatial operator and spatial function:
A spatial operator takes advantage of spatial indexes while a spatial function does not.
In your case, sdo_geom.sdo_relate is a spatial operator and sdo_geom.relate is a spatial function.
They serve the same functionality but might have huge performance difference if you have a big table.
In general, the complexity (performance) for spatial operators is O(ln N) and, spatial functions, O(N), while N is the number of geometry you will query against.
This is true for all Oracle Spatial operators and their corresponding spatial functions.
So try to use spatial operators in your query if they are available.
Jack