SDO_TOPO_MAP.VALIDATE

Format

SDO_TOPO_MAP.VALIDATE_TOPOLOGY(     
  topology  IN VARCHAR2,      
) RETURN VARCHAR2;

or

SDO_TOPO_MAP.VALIDATE_TOPOLOGY(
  topology         IN VARCHAR2,
  prevent_updates  IN VARCHAR2,
  level            IN NUMBER DEFAULT 1      
) RETURN VARCHAR2;

or

SDO_TOPO_MAP.VALIDATE_TOPOLOGY(
  topology  IN VARCHAR2,
  xmin      IN NUMBER,
  ymin      IN NUMBER,  
  xmax      IN NUMBER,
  ymax      IN NUMBER      
) RETURN VARCHAR2;

or

SDO_TOPO_MAP.VALIDATE_TOPOLOGY(
  topology  IN VARCHAR2,
  xmin      IN NUMBER,
  ymin      IN NUMBER,  
  xmax      IN NUMBER,
  ymax      IN NUMBER      
) RETURN VARCHAR2;

Description

Loads an entire topology or a window (rectangular portion) of a topology into a TopoMap object; returns the string TRUE if the structure of the topology is consistent, and raises an exception if the structure of the topology is not consistent.

Parameters

topology

Name of the topology to be validated. Must not exceed 20 characters.

xmin

Lower-left X coordinate value for the window (rectangular portion of the topology) to be validated.

ymin

Lower-left Y coordinate value for the window (rectangular portion of the topology) to be validated.

xmax

Upper-right X coordinate value for the window (rectangular portion of the topology) to be validated.

ymax

Upper-right Y coordinate value for the window (rectangular portion of the topology) to be validated.

prevent_updates

TRUE prevents other users from updating the topology while the validation is being performed; FALSE allows other users to update the topology while the validation is being performed. If you specify FALSE, any topology changes made by other users while the validation is being performed will not be considered by this function and will not affect the result.

level

A value of 0 checks for the following conditions:

All faces are closed, and none have infinite loops.
All previous and next edge pointers are consistent.
All edges meet at nodes.
Each island node is associated with a face.
All edges on a face boundary are associated with the face.

A value of 1 (the default) checks for all conditions associated with a value of 0, plus the following conditions related to computational geometry:

Each island is inside the boundary of its associated face.
No edge intersects itself or another edge.
Start and end coordinates of edges match coordinates of nodes.
Node stars are properly ordered geometrically.

Usage Notes

This function implicitly creates a TopoMap object, and removes the object after the validation is complete. (TopoMap objects are described in TopoMap Objects.)

This function uses a tolerance value of 10E-15 for its internal computations, as explained in Tolerance in the Topology Data Model.

Examples

The following example validates the topology named CITY_DATA, and it returns a result indicating that the topology is valid. (The example refers to definitions and data from Topology Built from Topology Data.)

CALL SDO_TOPO_MAP.VALIDATE_TOPOLOGY('CITY_DATA') INTO :res_varchar;
 
Call completed.
 
PRINT res_varchar;
 
RES_VARCHAR
--------------------------------------------------------------------------------
TRUE