When performing an Oracle export with the Export utility or Data Pump, and exporting a table containing an st_geometry attribute with an st_spatial_index, the index is exported.
With ArcGIS 9.2, when the export is performed, the st_geometry attribute's spatial index is exported, and during the import operation, the index is imported.
The ESRI st_geometry implementation defines the behavior of how the st_geometry attribute, spatial index, and metadata is handled during an Oracle export operation. This implementation is limited by the fact that Oracle's Object Extensibility documentation does not describe how to avoid exporting a secondary table object (the st_geometry's st_spatial_index object) during an Oracle export. This limitation means that the st_spatial_index object is unavoidably exported by default, if it exists.