Trying to get multiple cell values within a geometry

Question

I am provided with 3 tables:
1 - The GeoRaster
2 - The geoRasterData table
3 - A VAT table who's PK is the cell value from the above tables
Currently the user can select a point in our application and by using the getCellValue we get the cell value which is the PK on the 3rd table and this gives us the details to return to the user.
We now want to give the worst scenario within a given geometry or distance. So if I get back all the cell values within a given geometry/distance I can then call my other functions against the 3rd table to get the worst scores.
I had a conversation open for this before where JeffreyXie had some brilliant input, but it got archived while I was waiting on Oracle to resolve a bug (about 7 months)
See:
Trying to get multiple cell values within a geometry
If I am looking to get a list of cell values that interact with my geometry/distance and then loop through them, is there a better way?
BTW, if anybody wants to play with this functionality, it only seems to work in 11.2.0.4.
Below is the code I was using last, I think it is trying to get the cell values but the numbers coming back are not correct, I think I am converting the binary to integer wrong.
Any ideas?
CREATE OR REPLACE FUNCTION GEOSUK.getCellValuesInGeom_FNC RETURN VARCHAR2 AS
gr sdo_georaster;
lb blob;
win1 sdo_geometry;
win2 sdo_number_array;
status VARCHAR2(1000) := NULL;
CDP varchar2(80);
FLT number := 0;
cdl number;
vals varchar2(32000) := null;
VAL number;
amt0 integer;
amt integer;
off integer;
len integer;
buf raw(32767);
MAXV number := null;
r1 raw(1);
r2 raw(2);
r4 raw(200);
r8 raw(8);
MATCH varchar2(10) := '';
ROW_COUNT integer := 0;
COL_COUNT integer := 0;
ROW_CUR integer := 0;
COL_CUR integer := 0;
CUR_XOFFSET integer := 0;
CUR_YOFFSET integer := 0;
ORIGINY integer := 0;
ORIGINX integer := 0;
XOFF number(38,0) := 0;
YOFF number(38,0) := 0;
BEGIN
status := '1';
SELECT a.georaster INTO gr FROM JBA_MEGARASTER_1012 a WHERE id=1;
-- first figure out the celldepth from the metadata
cdp := gr.metadata.extract('/georasterMetadata/rasterInfo/cellDepth/text()',
'xmlns=http://xmlns.oracle.com/spatial/georaster').getStringVal();
if cdp = '32BIT_REAL' then
flt := 1;
end if;
cdl := sdo_geor.getCellDepth(gr);
if cdl < 8 then
-- if celldepth<8bit, get the cell values as 8bit integers
cdl := 8;
end if;
dbms_lob.createTemporary(lb, TRUE);
status := '2';
-- querying/clipping polygon
win1 := SDO_GEOM.SDO_BUFFER(SDO_GEOMETRY(2001,27700,MDSYS.SDO_POINT_TYPE(473517,173650.3, NULL),NULL,NULL), 10, .005);
status := '1.2';
sdo_geor.getRasterSubset(gr, 0, win1, '1',
lb, win2, NULL, NULL, 'TRUE');
-- Then work on the resulting subset stored in lb.
status := '2.3';
DBMS_OUTPUT.PUT_LINE ( 'cdl: '||cdl );
len := dbms_lob.getlength(lb);
cdl := cdl / 8;
-- make sure to read all the bytes of a cell value at one run
amt := floor(32767 / cdl) * cdl;
amt0 := amt;
status := '3';
ROW_COUNT := (WIN2(3) - WIN2(1))+1;
COL_COUNT := (WIN2(4) - WIN2(2))+1;
--NEED TO FETCH FROM RASTER
ORIGINY := 979405;
ORIGINX := 91685;
--CALCUALATE BLOB AREA
YOFF := ORIGINY - (WIN2(1) * 5); --177005;
XOFF := ORIGINX + (WIN2(2) * 5); --530505;
status := '4';
--LOOP CELLS
off := 1;
WHILE off <= LEN LOOP
dbms_lob.read(lb, amt, off, buf);
for I in 1..AMT/CDL LOOP
if cdl = 1 then
r1 := utl_raw.substr(buf, (i-1)*cdl+1, cdl);
VAL := UTL_RAW.CAST_TO_BINARY_INTEGER(R1);
elsif cdl = 2 then
r2 := utl_raw.substr(buf, (i-1)*cdl+1, cdl);
val := utl_raw.cast_to_binary_integer(r2);
ELSIF CDL = 4 then
IF (((i-1)*cdl+1) + cdl) > len THEN
r4 := utl_raw.substr(buf, (i-1)*cdl+1, (len - ((i-1)*cdl+1)));
ELSE
r4 := utl_raw.substr(buf, (i-1)*cdl+1, cdl+1);
END IF;
if flt = 0 then
val := utl_raw.cast_to_binary_integer(r4);
else
val := utl_raw.cast_to_binary_float(r4);
end if;
elsif cdl = 8 then
r8 := utl_raw.substr(buf, (i-1)*cdl+1, cdl);
val := utl_raw.cast_to_binary_double(r8);
end if;
if MAXV is null or MAXV < VAL then
MAXV := VAL;
end if;
IF i = 1 THEN
VALS := VALS || VAL;
ELSE
VALS := VALS ||'|'|| VAL;
END IF;
end loop;
off := off+amt;
amt := amt0;
end loop;
dbms_lob.freeTemporary(lb);
status := '5';
RETURN VALS;
EXCEPTION
    WHEN OTHERS THEN
        RAISE_APPLICATION_ERROR(-20001, 'GENERAL ERROR IN MY PROC, Status: '||status||', SQL ERROR: '||SQLERRM);
END;

Answer 1

Hey guys,
Zzhang,
That's a good spot and as it happens I spotted that and that is why I am sure I am querying that lob wrong. I always get the a logic going past the total length of the lob.
I think I am ok using 11.2.0.4, if I can get this working it is really important to us, so saying to roll up to 11.2.0.4 for this would be no problem.
The error in 11.2.0.3 was an internal error: [kghstack_underflow_internal_3].
Something that I think I need to find out more about, but am struggling to get more information on is, I am assuming that the lob that is returned is all cell values or at lest an array of 4 byte (32 bit) chunks, although, I don't know this.
Is that a correct assumption or is there more to it?
Have either of you seen any documentation on how to query this lob?
Thanks