SDO_DISTANCE - Tolerance

Question

If I have 2 point parms (not layers), with lat/longs with decimal places from 5 to 7 long, and I wanted to calculate the distance to within 5 CM, the formula would be:
SELECT MDSYS.SDO_GEOM.SDO_DISTANCE(
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(f_long,f_lat,NULL),NULL,NULL),
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(t_long,t_lat,NULL),NULL,NULL),
.05,'unit=KM' ) AS km_dist2 FROM dual;
What would be the equivalent (roughly within 5 cm) using a unit=MILE? Would I need to use a Tolerance of .0005?
SELECT MDSYS.SDO_GEOM.SDO_DISTANCE(
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(f_long,f_lat,NULL),NULL,NULL),
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(t_long,t_lat,NULL),NULL,NULL),
.0005,'unit=MILE' ) AS mi_dist2 FROM dual;
Thanks,
JB

Answer 1

It looks like the Tolerance Check is ALWAYS being done against Meters, even though, the Unit is either KM or MILE. It looks like if we were to set the tolerance to 0.05 it will always consider any 2 points as 1 point ONLY IF they are within approx. 5 CM of each other, even if MILE is specified as the UNIT?
SELECT MDSYS.SDO_GEOM.SDO_DISTANCE(
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.514366,43.072118,NULL),NULL,NULL),
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.2879915,43.1564514,NULL),NULL,NULL),
18300,'unit=KM' ) AS km_dist2 FROM dual;
Result = 20.6698332651529
SELECT MDSYS.SDO_GEOM.SDO_DISTANCE(
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.514366,43.072118,NULL),NULL,NULL),
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.2879915,43.1564514,NULL),NULL,NULL),
18325,'unit=KM' ) AS km_dist2 FROM dual;
Result = 0.0
SELECT MDSYS.SDO_GEOM.SDO_DISTANCE(
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.514366,43.072118,NULL),NULL,NULL),
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.2879915,43.1564514,NULL),NULL,NULL),
18300,'unit=MILE' ) AS km_dist2 FROM dual;
Result = 12.843638939315
SELECT MDSYS.SDO_GEOM.SDO_DISTANCE(
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.514366,43.072118,NULL),NULL,NULL),
mdsys.sdo_geometry(2001,8307,mdsys.sdo_point_type(-89.2879915,43.1564514,NULL),NULL,NULL),
18325,'unit=MILE' ) AS km_dist2 FROM dual;
Result = 0.0