'Return any spatial index creation SQL for the field.'

def sql_indexes_for_field(self, model, f, style):

    from django.contrib.gis.db.models.fields import GeometryField
    output = super(OracleCreation, self).sql_indexes_for_field(model, f, style)
    if isinstance(f, GeometryField):
        gqn = self.connection.ops.geo_quote_name
        qn = self.connection.ops.quote_name
        db_table = model._meta.db_table
        output.append((((((((((((((((style.SQL_KEYWORD('INSERT    INTO    ') + style.SQL_TABLE('USER_SDO_GEOM_METADATA')) + ('    (%s,    %s,    %s,    %s)\n        ' % tuple(map(qn, ['TABLE_NAME', 'COLUMN_NAME', 'DIMINFO', 'SRID'])))) + style.SQL_KEYWORD('    VALUES    ')) + '(\n                ') + style.SQL_TABLE(gqn(db_table))) + ',\n                ') + style.SQL_FIELD(gqn(f.column))) + ',\n                ') + style.SQL_KEYWORD('MDSYS.SDO_DIM_ARRAY')) + '(\n                        ') + style.SQL_KEYWORD('MDSYS.SDO_DIM_ELEMENT')) + ("('LONG',    %s,    %s,    %s),\n                        " % (f._extent[0], f._extent[2], f._tolerance))) + style.SQL_KEYWORD('MDSYS.SDO_DIM_ELEMENT')) + ("('LAT',    %s,    %s,    %s)\n                ),\n" % (f._extent[1], f._extent[3], f._tolerance))) + ('                %s\n        );' % f.srid)))
        if f.spatial_index:
            idx_name = truncate_name(('%s_%s_id' % (db_table, f.column)), 30)
            output.append((((((((((style.SQL_KEYWORD('CREATE    INDEX    ') + style.SQL_TABLE(qn(idx_name))) + style.SQL_KEYWORD('    ON    ')) + style.SQL_TABLE(qn(db_table))) + '(') + style.SQL_FIELD(qn(f.column))) + ')    ') + style.SQL_KEYWORD('INDEXTYPE    IS    ')) + style.SQL_TABLE('MDSYS.SPATIAL_INDEX')) + ';'))
    return output
