When you attempt to add an ST_GEOMETRY or SDO_GEOMETRY column to a populated table, the following error occurs:
'ORA-01758: table must be empty to add mandatory (NOT NULL) column.'
Examples include loading a raster with the sderaster command as SDO_GEOMETRY or ST_GEOMETRY and attempting to register it with the geodatabase. This causes the data to become unusable. Also, raster catalogs created outside of ArcObjects cannot be registered with the geodatabase.