Update of /cvsroot/monetdb/MonetDB5/src/modules/mal
In directory sc8-pr-cvs16.sourceforge.net:/tmp/cvs-serv22469
Modified Files:
bpm.mx
Log Message:
Inclusion of the oracle partitioning scheme.
Index: bpm.mx
===================================================================
RCS file: /cvsroot/monetdb/MonetDB5/src/modules/mal/bpm.mx,v
retrieving revision 1.86
retrieving revision 1.87
diff -u -d -r1.86 -r1.87
--- bpm.mx 8 Jun 2007 19:46:23 -0000 1.86
+++ bpm.mx 9 Jun 2007 07:07:01 -0000 1.87
@@ -263,6 +263,9 @@
command count(b:bat[:any_1,:any_2]):int
address BPMcount;
+command pieces(b:bat[:any_1,:any_2]):int
+address BPMpieces
+comment "Count the number of partitions";
@-
The partitioning is handled inside the module.
If the alias BAT denotes an existing partition, it is
@@ -500,6 +503,7 @@
bpm_export str BPMhashPartitions(int *ret, bat *bid);
bpm_export str BPMcount(int *ret, bat *src);
+bpm_export str BPMpieces(int *ret, bat *src);
bpm_export str BPMglue(int *ret, bat *src);
bpm_export str BPMaddSegment(int *ret, bat *dst, bat *src);
@@ -508,6 +512,7 @@
bpm_export str BPMhash(bat *ret, bat *bid, int *slots);
bpm_export str BPMderived(bat *ret, bat *bid, bat *src);
bpm_export str BPMadapt(bat *ret, bat *bid, ptr low, ptr hgh, bat *rs );
+bpm_export str BPMoracle(bat *ret, bat *bid, ptr low, ptr hgh, bat *rs );
bpm_export str BPMtake(bat *ret, str *nme);
bpm_export str BPMtakePartition(bat *ret, bat *bid, int *idx);
@@ -1239,6 +1244,19 @@
}
return MAL_SUCCEED;
}
+str
+BPMpieces(int *ret, bat *bid)
+{
+ int i;
+ Partition ps;
+ *ret= 0;
+ if( (ps= getAlias(*bid)) == 0)
+ throw(MAL,"pbm.count","Partitioned BAT not found");
+ for(i= ps->nxt ; i!=ps->bid && bpmcat[i] ; i= bpmcat[i]->nxt){
+ *ret +=1;
+ }
+ return MAL_SUCCEED;
+}
str
BPMglue(bat *ret, bat *bid){
@@ -1462,12 +1480,14 @@
size of the pieces produced. They may not get too small.
The ORACLEPOLICY implements a random decision based
-on the depth of the segementation sequence and relative sizes.
+on a Gaussian distribution, the total number of fragments
+and the relative size of the piece to be broken op.
@c
#define SIZEPOLICY 1
#define ORACLEPOLICY 2
-static int BPMsizePolicy( BAT *b, BAT *bs, int *bid, ptr low, ptr hgh)
+static int
+BPMsizePolicy( BAT *b, BAT *bs, int *bid, ptr low, ptr hgh)
{
int cs=0;
lng space, space1, space2;
@@ -1496,6 +1516,31 @@
return cs;
}
+static double
+gaussian(double x, double sigma, double m){
+ double s2= sigma*sigma;
+ double f1= 1.0/(sigma *sqrt(2*M_PI));
+ double f2= f1 * exp(-(x-m)*(x-m)/(2*s2));
+ return f2;
+}
+
+static int
+BPMoraclePolicy(BAT *b, BAT *rs )
+{
+ int pieces;
+ double rnd, threshold, g;
+
+ BPMpieces(&pieces,&b->batCacheid);
+ rnd= rand()/(double)RAND_MAX;
+ threshold= (double)BATcount(rs)/BATcount(b);
+ g= gaussian(rnd,1.0/pieces,0.5)/ gaussian(0.5,1.0/pieces,0.5);
+#ifdef _DEBUG_BPM_
+ streamm_printf(GDKout,"oracle pieces %d rnd %f threshold %f gaussian
%f\n",
+ pieces,rnd,threshold,guassian);
+#endif
+ return g*threshold >rnd;
+}
+
static str
BPMadaptImpl(int *ret, bat *bid, ptr low, ptr hgh, bat *rs, int policy )
{
@@ -1533,9 +1578,12 @@
BBPunfix(b->batCacheid);
return MAL_SUCCEED;
}
+
@:getBATdescriptor(rs,bs,"bpm.adapt");
if( policy == SIZEPOLICY)
cs= BPMsizePolicy(b,bs,bid,low,hgh);
+ if( policy == ORACLEPOLICY && BPMoraclePolicy(b,bs))
+ cs= 4; /* to be refined */
if( cs==0){
BBPunfix(b->batCacheid);
BBPunfix(bs->batCacheid);
@@ -1548,11 +1596,11 @@
vp= (ValPtr) GDKzalloc(sizeof(ValRecord));
VALinit(vp,b->ttype,nilptr);
findMedian(vp,b);
- #ifdef _DEBUG_BPM_
+#ifdef _DEBUG_BPM_
stream_printf(GDKout,"Found median ");
VALprint(GDKout,vp);
stream_printf(GDKout,"\n");
- #endif
+#endif
low = (ptr) VALget(vp);
if( *bid > 0)
bs1= BAT_select_(b, low, nilptr, TRUE, FALSE, TRUE,
FALSE);
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