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FAQ: Why is no data returned for a spatial selection or identify operation on very large geodetic features stored in an Oracle Spatial database?

Question

Why is no data returned for a spatial selection or identify operation on very large geodetic features stored in an Oracle Spatial database?

Answer

Identify or spatial selection operations may fail to return any data when the selection point is nearer the midpoint of a long line segment and further from the vertices of the feature.

This is expected behavior for data stored in a geodetic coordinate system in an Oracle Spatial database.

Data stored in a geodetic coordinate system follows the curvature of the earth. Over large distances, this curvature is great enough that the search window is not proximate to the line; you are clicking or selecting what looks to ArcGIS to be a straight line (in Cartesian space), but using Great Circle paths, the data is actually a curved line in the Oracle Spatial database. Therefore, the spatial query window does not cross the actual path of the line and does not return any rows.