6 SDO_GEOR_UTL Package Reference

The MDSYS.SDO_GEOR_UTL package contains subprograms (functions and procedures) for utility operations related to GeoRaster. This chapter presents reference information, with one or more examples, for each subprogram.

SDO_GEOR_UTL.calcOptimizedBlockSize

Format

SDO_GEOR_UTL.calcOptimizedBlockSize(

dimensionSize IN SDO_NUMBER_ARRAY,

blockSize IN OUT SDO_NUMBER_ARRAY,

pyramidLevel IN number default 0);

Description

Calculates an optimal blockSize value that will use less padding space in the GeoRaster object storage, based on the GeoRaster dimension sizes and the user-specified block size values.

Parameters

dimensionSize: Dimension size array of the GeoRaster object.
blockSize: Block size array, which holds the user-specified block size values and into which the procedure outputs the adjusted optimal block size values.
pyramidLevel: Maximum pyramid level. The default value is 0.

Usage Notes

This procedure enables you to give desired block size values (which may not be optimal), automatically adjust them, and then determine the block size array values for a specified GeoRaster dimension size array that will be optimal for reducing the amount of padding space in GeoRaster object storage. The adjustment is always made around the user-specified values. For more information, see the explanations of the blocking and blockSize keywords in Table 1-1, "storageParam Keywords for Raster Data" in Section 1.4.1.

An exception is generated if the input dimensionSize or blockSize parameter contains any invalid values.

Examples

The following example calculates and displays an optimal block size value, based on a specified dimension size array of (12371,11261,13) and a specified block size array of (512,512,5). Note that the optimal rowBlockSize value returned is 538 as opposed to the original value of 512, and the optimal bandBlockSize value returned is 1 as opposed to the original value of 5.

DECLARE
  dimensionSize    sdo_number_array;
  blockSize        sdo_number_array;
BEGIN
  dimensionSize:=sdo_number_array(12371,11261,13);
  blockSize:=sdo_number_array(512,512,5);
  sdo_geor_utl.calcOptimizedBlockSize(dimensionSize,blockSize);
  dbms_output.put_line('Optimized rowBlockSize = '||blockSize(1));
  dbms_output.put_line('Optimized colBlockSize = '||blockSize(2));
  dbms_output.put_line('Optimized bandBlockSize = '||blockSize(3));
END;
/
Optimized rowBlockSize = 538
Optimized colBlockSize = 512
Optimized bandBlockSize = 1

SDO_GEOR_UTL.calcRasterNominalSize

Format

SDO_GEOR_UTL.calcRasterNominalSize(

geor IN SDO_GEORASTER,

padding IN VARCHAR2 DEFAULT 'TRUE',

pyramid IN VARCHAR2 DEFAULT 'TRUE',

bitmapMask IN VARCHAR2 DEFAULT 'TRUE'

) RETURN NUMBER;

Description

Returns the total raster block length (in bytes) of a GeoRaster object, as if it were not compressed and did not contain any empty raster blocks.

Parameters

geor: GeoRaster object.
padding: The string TRUE (the default) causes padding in the raster blocks to be considered; the string FALSE causes padding in the raster blocks not to be considered.
pyramid: The string TRUE (the default) causes the size of any pyramids to be considered; the string FALSE causes the size of any pyramids not to be considered.
bitmapMask: The string TRUE (the default) causes any associated bitmap masks to be considered; the string FALSE causes any associated bitmap masks not to be considered. For an explanation of bitmap masks, see Section 1.8.

Usage Notes

This function does not consider any LOB storage overhead, so the result is only an approximation of the real storage requirements for the GeoRaster object.

The result of this function will be greater than or equal to the result of the SDO_GEOR_UTL.calcRasterStorageSize function on the same GeoRaster object. If this function returns a larger value than the SDO_GEOR_UTL.calcRasterStorageSize function on the same GeoRaster object, the difference in the values reflects the space saved by the use of compression or empty raster blocks, or both.

For information about GeoRaster compression, see Section 1.10.

Examples

The following example calculates the nominal raster size (in bytes) of a GeoRaster object, according to its current blocking scheme. The returned size includes (by default) any padding in the raster blocks, any associated bitmap masks, and any pyramids.

SELECT SDO_GEOR_UTL.calcRasterNominalSize(georaster) nsize FROM georaster_table 
  WHERE georid=1;

     NSIZE
----------
    289150

SDO_GEOR_UTL.calcRasterStorageSize

Format

SDO_GEOR_UTL.calcRasterStorageSize(

geor IN SDO_GEORASTER

) RETURN NUMBER;

Description

Returns the actual length (in bytes) of all raster blocks of a GeoRaster object.

Parameters

geor: GeoRaster object.

Usage Notes

The function calculates the actual length of all raster blocks of a GeoRaster object. It does not consider any LOB storage overhead, so the result is only an approximation of the real storage size of the GeoRaster object. In essence, this function executes the following statement:

EXECUTE IMMEDIATE
'SELECT SUM(DBMS_LOB.getLength(rasterBlock)) FROM ' || geor.rasterDataTable || ' WHERE rasterId=' || geor.rasterId;

The result of this function will be less than or equal to the result of the SDO_GEOR_UTL.calcRasterNominalSize function on the same GeoRaster object. If this function returns a smaller value than the SDO_GEOR_UTL.calcRasterNominalSize function on the same GeoRaster object, the difference in the values reflects the space saved by the use of compression or empty raster blocks, or both.

Examples

The following example calculates ratio (as a decimal fraction) of the actual size to the nominal size of a specified GeoRaster object. In this example, the actual size is about one-twentieth (1/20) of the nominal size.

SELECT SDO_GEOR_UTL.calcRasterStorageSize(georaster)/
  SDO_GEOR_UTL.calcRasterNominalSize(georaster) ratio
    FROM georaster_table WHERE georid=1;

     RATIO
----------
.056198816

SDO_GEOR_UTL.createDMLTrigger

Format

SDO_GEOR_UTL.createDMLTrigger(

tableName VARCHAR2,

columnName VARCHAR2);

Description

Creates the required standard GeoRaster data manipulation language (DML) trigger on a GeoRaster column in a GeoRaster table, so that the appropriate operations are performed when its associated trigger is fired.

Parameters

tableName: Name of a GeoRaster table (the table containing rows with at least one GeoRaster object column).
columnName: Name of a column of type SDO_GEORASTER in the GeoRaster table.

Usage Notes

As explained in Section 3.1.3, to ensure the consistency and integrity of internal GeoRaster tables and data structures, GeoRaster automatically creates a unique DML trigger for each GeoRaster column whenever a user creates a GeoRaster table (that is, a table with at least one GeoRaster column), with the following exception: if you use the ALTER TABLE statement to add one or more GeoRaster columns. In this case, you must call the SDO_GEOR_UTL.createDMLTrigger procedure to create the DML trigger on each added GeoRaster column.

Otherwise, you usually do not need to call this procedure, although but it is still useful for re-creating the DML trigger in some scenarios, such as a database upgrade or a data migration.

Examples

The following example creates the standard GeoRaster DML trigger for a table named XYZ_GEOR_TAB containing a GeoRaster column named GEOR_COL.

EXECUTE sdo_geor_utl.createDMLTrigger('XYZ_GEOR_TAB', 'GEOR_COL');

SDO_GEOR_UTL.fillEmptyBlocks

Format

SDO_GEOR_UTL.fillEmptyBlocks(

georaster IN OUT SDO_GEORASTER,

bgValues IN SDO_NUMBER_ARRAY DEFAULT NULL);

Description

Fills in all empty blocks with specified background values.

Parameters

georaster: GeoRaster object in which to fill empty blocks.
bgValues: Background values for filling empty raster blocks. The number of elements in the SDO_NUMBER_ARRAY object must be either one (same filling value used for all bands) or the band dimension size (a different filling value for each band, respectively). For example, SDO_NUMBER_ARRAY(1,5,10) fills the first band with 1, the second band with 5, and the third band with 10. If this parameter is null, then bgValues will be 0 (zero).

Usage Notes

If georaster is null, this procedure performs no operation.

If pyramid data exists for georaster, the pyramid is regenerated based on pyramid information stored in the metadata.

Examples

The following example fills all empty blocks with background values (255,0,0).

DECLARE
  geor  SDO_GEORASTER;
BEGIN
  SELECT georaster INTO geor FROM georaster_table WHERE georid = 3 FOR UPDATE;
  SDO_GEOR_UTL.fillEmptyBlocks(geor, SDO_NUMBER_ARRAY(255,0,0));
  UPDATE georaster_table SET georaster = geor WHERE georid = 3;
  COMMIT;
END;
/

SDO_GEOR_UTL.makeRDTNamesUnique

Format

SDO_GEOR_UTL.makeRDTNamesUnique;

Description

Renames some existing registered raster data tables that do not have unique names so that all raster data table names are unique within the database, and updates the GeoRaster system data and all affected GeoRaster objects to reflect the new names.

Parameters

None.

Usage Notes

If one or more registered raster data tables have the same name (under different schemas), you can use this procedure or the SDO_GEOR_UTL.renameRDT procedure, or both, to eliminate the duplication.

Run this procedure when you are connected to the database with the DBA role.

This procedure is not transactional, and the result cannot be rolled back.

Examples

The following example automatically renames some existing registered raster data tables that do not have unique names so that all registered raster data table names are unique within the database, and it updates the GeoRaster system data and all affected GeoRaster objects to reflect the new names.

EXECUTE sdo_geor_utl.makeRDTNamesUnique;

SDO_GEOR_UTL.renameRDT

Format

SDO_GEOR_UTL.renameRDT(

oldRDTs VARCHAR2,

newRDTs VARCHAR2 DEFAULT NULL);

Description

Renames one or more existing registered raster data tables owned by the current user, and updates the GeoRaster system data and all affected GeoRaster objects to reflect the new names.

Parameters

oldRDTs: Name of the registered raster data table or tables to be renamed. For multiple tables, use a comma-delimited list.
newRDTs: New names to be assigned to the raster data table or tables that are specified in oldRDTs. For multiple tables, use a comma-delimited list with an order exactly reflecting the names in oldRDTs. If this parameter is null, GeoRaster assigns a unique new name to each input raster data table.

Usage Notes

If one or more registered raster data tables owned by different users have the same name, you can use this procedure or the SDO_GEOR_UTL.makeRDTNamesUnique procedure, or both, to eliminate the duplication.

Before using this procedure, you must connect to the database as the owner of the raster data table or tables. You cannot use this procedure to rename a raster data table owned by another user.

If any table in oldRDTs is not included in the GeoRaster system data, it is ignored.

If any table in newRDTs conflicts with a name in the GeoRaster system data or with the name of another object owned by the current user, an exception is raised.

This procedure is not transactional, and the result cannot be rolled back.

Examples

The following example renames the registered raster data tables RDT_1 and RDT_2 to ST_RDT_1 and ST_RDT_2, respectively.

EXECUTE sdo_geor_utl.renameRDT('RDT_1,RDT_2','ST_RDT_1,ST_RDT_2');