How to Rebuild Spatial Index???

When I excute "truncate table ..." or "delete from ...", sometimes I encounter ORA-29859 or ORA-29861 error. In most cases, I just rebuild the spatial index on the geometry column and the problem will be fixed.

For Example:
DROP INDEX GEO_PS_POSITION_SX;
CREATE INDEX GEO_PS_POSITION_SX ON GEO_PS_POSITION (ROUTE) INDEXTYPE IS MDSYS.SPATIAL_INDEX;