SDO_GEOR.getNODATA

Format

SDO_GEOR.getNODATA(
     georaster   IN SDO_GEORASTER, 
     layerNumber IN NUMBER 
     ) RETURN SDO_RANGE_ARRAY;

Description

Returns the values or value ranges that represent NODATA cells in a GeoRaster object (in ascending order, without duplicates).

Parameters

georaster: GeoRaster object.
layerNumber: Layer number in the GeoRaster object. A value of 0 (zero) indicates the object layer.

Usage Notes

Some cells of a GeoRaster object may have no meaningful value assigned or collected. Such cells contain a NODATA value are thus called NODATA cells, which means that those cells are not semantically defined. The application is responsible for defining the meaning or significance of cells identified as NODATA cells. For more information about NODATA values and value ranges, see NODATA Values and Value Ranges.

This function returns all the NODATA values and value ranges associated with a specified raster layer of the specified GeoRaster object, in ascending order and in a compact form with duplicates eliminated. The set of NODATA values and value ranges associated with a sublayer (layerNumber > 0) is always a superset of the values and value ranges of the object layer (layerNumber = 0). The result for a sublayer is the combination of the NODATA metadata entries for the specified sublayer, the object layer, and any pre-release 11g NODATA metadata stored as part of the raster description information.

If the specified GeoRaster object or layer has more than one NODATA value, you must use the function format that returns an SDO_RANGE_ARRAY object. The SDO_RANGE_ARRAY type is described in NODATA Values and Value Ranges.

If this function returns a null value, it means that all cells of the GeoRaster object or of the specified layer are defined and have a meaningful cell value.

To specify the NODATA values for a GeoRaster object, use the SDO_GEOR.addNODATA procedure.

Examples

The following example returns the value to be used for NODATA cells in the GeoRaster objects (GEORASTER column) in table GEORASTER_TABLE, whose definition is presented after Example 1-1 in Storage Parameters.

SELECT SDO_GEOR.getNODATA(georaster, 0) NODATA FROM georaster_table WHERE georid=0;

NODATA
------------
SDO_RANGE_ARRAY(SDO_RANGE(5,7))