Oracle Spatial User's Guide and Reference - InfoLab

SDO_UTIL.REMOVE_DUPLICATE_VERTICES
Format
Description
Parameters
Usage Notes
Examples
SDO_UTIL.REMOVE_DUPLICATE_VERTICES
geometry IN SDO_GEOMETRY,
tolerance IN NUMBER
) RETURN SDO_GEOMETRY;
Removes duplicate (redundant) vertices from a geometry.
geometry
Geometry from which to remove duplicate vertices.
tolerance
Tolerance value (see Section 1.5.5).
SDO_UTIL.REMOVE_DUPLICATE_VERTICES
When two consecutive vertices in a geometry are the same or within the tolerance
value associated with the geometry, Spatial considers the geometry to be invalid.
The Spatial geometry validation functions return the error ORA-13356 in these
cases. You can use the REMOVE_DUPLICATE_VERTICES function to change such
invalid geometries into valid geometries.
If the input geometry does not contain any duplicate vertices, it is returned.
The following example removes a duplicate vertex from the input geometry, which
is the same geometry as cola_b (see Figure 2–1 and Example 2–1 in Section 2.1)
except that it has been deliberately made invalid by adding a third vertex that is the
same point as the second vertex (8,1).
SELECT SDO_UTIL.REMOVE_DUPLICATE_VERTICES(
SDO_GEOMETRY(
2003, -- two-dimensional polygon
Spatial Utility Subprograms 19-27