Editing with map topology

To edit features with map topology, you build a map topology during an edit session. Once you have created the map topology, spatial relationships are discovered on the fly and the topology cache is built. The topology cache stores coincident areas among the features visible in the current map extent in memory on your local computer.

In the topology cache, spatial relationships are stored between the parts of the features rather than the features themselves. Shared segments are called edges. The beginning and ending points of an edge are called nodes.

After a map topology is built, the topology cache stores shared segments between features as edges (pink). The beginning and ending points of edges (hollow circles) are stored as nodes.

To simultaneously edit features in a topology, you modify edges and nodes. The simplest topology editing task is moving an edge or a node.

To move the boundary between adjacent features, you move the shared edge.

You can also reshape an edge by adding new vertices.

To edit the shape of the boundary between two adjacent features, you can reshape the shared edge.

When you build a map topology, you choose the layers (one or more) that will participate. For example, to move the boundary between two adjacent parcels, you would build a map topology that included only the parcels layer, then move the shared edge between the two features.

To reshape a street feature that coincides with a bus route, you would build a map topology that included both the streets and the bus routes layers. You would then reshape the shared edge between the street and bus route. Both features would be edited simultaneously.