SDO_RELATE command with 'coveredby' option doesnt return record as expected

Question

Hi all,
I use oracle spatial 10.2. I use sdo_relate to compare 2 tables' geometries. The case is table 1 has ~2000 records, each is a retangle and has sdo_geometry field. 'Table 2' is transient geometry defined by sdo_geometry to a rectengle.
The definition of the table 2 is:
SDO_GEOMETRY(2003, NULL,NULL, SDO_ELEM_INFO_ARRAY(1,1003,3), SDO_ORDINATE_ARRAY(-50,50, 50,-50)), 'mask=COVEREDBY') = 'TRUE';
I am working in world coordinates.
and the whole SQL for comparison is:
select name from KMK.summary where sdo_relate(mbr,SDO_GEOMETRY(2003, NULL,NULL, SDO_ELEM_INFO_ARRAY(1,1003,3), SDO_ORDINATE_ARRAY(-50,50, 50,-50)), 'mask=COVEREDBY') = 'TRUE';
The problem is that this command doesnt return any values, i.e no records are selected from table 1. I am sure that there are features that evaluate to true for 'mask=COVEREDBY'.
here is one of them:
SQL> SELECT SDO_AGGR_MBR(mbr) FROM kmk.summary where name = ' GETDB_GLOBAL_004065_00O';
SDO_AGGR_MBR(SHAPE)(SDO_GTYPE, SDO_SRID, SDO_POINT(X, Y, Z), SDO_ELEM_INFO, SDO_
SDO_GEOMETRY(2003, NULL, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR
AY(-50, -25.25, -48.25, -24.5))
this teature's MBR goes to -50 and it should be selected.
What do I wrong?
Thanks

Answer 1

Hi I will give it a try on Monday for the numwidth20
I tried with inside mask and it returns the right number of records - only those that are completely within/inside the mask. Thisone record is still not selected.
I use ARCGIS on the same table with SDE so I know what number of records to expect.
When you did the test was GETDB_GLOBAL_004065_00O selected with coveredby mask?
We are running v 10.2.0.3 could this make a difference?
It seems to me that when the coordinates are evaluated the algorithm uses the following for comparison:
(in case of coveredby/inside) it comapres every point to the mask pounts and if it is less than it returns FALSE, it doesn't check if is is equal as well to return TRUE. On the other hand it checks if it is more or equal and if it is returns TRUE. That is why it selects record that have one boundary on top of the search window but extent outside it.
EDIT: It seems it is the precision. When I set it to 25 it returned -50.0000000003723 for the Xmin.
Now, this table has been created from and ESRI shp file, imported to oracle using ArcSDE. Do you have any idea of shp files and how the precisions are utilized in oracle?
Edited by: garnet on Mar 16, 2009 10:13 AM
Edited by: garnet on Mar 16, 2009 4:31 PM