2 Editing Topologies

Node and edge data in a topology can be edited. The operations include adding, moving, and removing nodes and edges, and updating the coordinates of an edge.

This chapter explains two approaches to editing topology data, and it explains why one approach (creating and using a special cache) is better in most cases. It also describes the behavior and implications of some major types of editing operations.

The explanations in this chapter refer mainly to the PL/SQL application programming interface (API) provided in the MDSYS.SDO_TOPO_MAP package, which is documented in SDO_TOPO_MAP Package Subprograms. However, you can also perform topology editing operations using the client-side Java API, which is introduced in Topology Data Model Java Interface and is explained in the Javadoc-generated documentation.

To edit topology data, always use the PL/SQL or Java API. Do not try to perform editing operations by directly modifying the node, edge, or face information tables.

• Approaches for Editing Topology Data
  Whenever you need to edit a topology, you can use PL/SQL or Java API. In both cases, Oracle Spatial uses an in-memory topology cache, specifically, a TopoMap object.
• Performing Operations on Nodes
  This topic contains sections that describe the effects of adding, moving, and removing nodes, and that explain how to perform these operations using the PL/SQL API.
• Performing Operations on Edges
  This topic describes the effects of adding, moving, removing, and updating edges, and explains how to perform these operations using the PL/SQL API.

See Also:

• Cross-Schema Topology Editing