How to Mosaic 167,958 georasters?

Question

Hello,
I have a table named RASTER that contains 167,958 georasters. I have a table named RR_RDT that contains the blocks for the georasters. There are 65,284 georasters that have "content" and the remaining georasters are blanks that were generated to overcome the limitations of the MOSAIC operation, specifically the need for a rectangular boundary.
All the georasters are valid, have the same SRID, are non-overlapping and have had spatial extents generated. I have created a table named LL_ORTHO_06 and MLL_RDT to contain the results of the MOSAIC operation. I have attempted to use the sdo_geor.mosaic( ) command and run into an ORA: 04030 error, "out of process memory, cannot allocate 296 bytes'.
My inquiry to the community is has anyone been successful in creating a mosaic of 100,000 plus georaster objects in a single pass, or have you had to incrementally generate a mosaic.
I am tasked with creating a county wide mosaic of Orthoimagery that has pyramids and serving that data out via a WMS service using Mapviewer.
Have a great day,
Jerry Cox
GIS Analyst
Santa Clara Valley Water District
San Jose, CA

Answer 1

Hello,
In response to your inquiry for more details I submit the following:
1. The dbms version is 10.2.0.1.0 with Patch Set 2, 10.2.3.0 and Interim Patches # 5740875 and # 6812783.
2. The server has an Intel Xeon CPU, 4 Gb Ram and is running MS Server 2003, Service Pack 2
3. The georasters are contained in a single table named RASTER and an RDT table named RR_RDT
4. The mosaic will be contained in a single table named LL_ORTHO_06 and an RDT table named MLL_RDT
5. The georaster tiles/blocks are not compressed.
6. The mosaic will not be compressed.
7. The source of the georasters are 65,283 TIFF files, each being 11.768 MB in size, and georeferenced with a .tfw file.
8. The blocksize of the TIFF georasters is 256,256,3 and the interleaving is BIP.
9. The blocksize of the 102,674 Blank georasters is 256,256,3 and the interleaving is BIP.
10. All georasters are SRID 2207, georeferenced, non-overlapping and no gaps exist between any of the blocks.
11. The DBA has "tuned" the SGA, PGA and other memory parameters on the database server
12. The pl/sql used to create and populate the mosaic is:
-- Create the LL_Ortho_06 table
CREATE TABLE LL_ORTHO_06(GEORID NUMBER(15,0) NOT NULL, GEORASTER SDO_GEORASTER)
TABLESPACE MOSAICK_DATA
PCTFREE 0;
-- Create trigger
BEGIN
sdo_geor_utl.createDMLTrigger('LL_ORTHO_06', 'GEORASTER');
END;
-- Create LL_Ortho_06 object RDT
CREATE TABLE MLL_RDT OF SDO_RASTER
(PRIMARY KEY (rasterID, pyramidLevel, bandBlockNumber, rowBlockNumber, columnBlockNumber))
TABLESPACE MOSAICK_DATA NOLOGGING
LOB(rasterBlock) STORE AS lobsegmll
(TABLESPACE MOSAICK_DATA
CHUNK 8192
CACHE READS
NOLOGGING
PCTVERSION 0
STORAGE (PCTINCREASE 0)
and finally the pl/sql block that is failing to perform as expected is:
DECLARE
grobj sdo_georaster;
BEGIN
DBMS_OUTPUT.PUT_LINE('Mosaic Begin Time'||to_char(sysdate,'HH:MM:SS'));
INSERT INTO LL_ORTHO_06(georid,georaster) VALUES (1, sdo_geor.init('MLL_RDT',1)) RETURNING georaster INTO grobj;
sdo_geor.mosaic('RASTER','GEORASTER',grobj,'blocksize=(256,256,3)');
UPDATE LL_ORTHO_06 SET georaster = grobj WHERE georid = 1;
COMMIT;
DBMS_OUTPUT.PUT_LINE('Mosaic End Time'||to_char(sysdate,'HH:MM:SS'));
END;
The above code was used initially to create a "proof of concept" mosaic of 50 blank and non-blank georasters, which gave me the impression the same could be done with any number of georasters.
Thanks for your input,
Jerry Cox
GIS Analyst
Santa Clara Valley Water District
San Jose, CA