Changeset: 83e964c1508b for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=83e964c1508b
Modified Files:
monetdb5/extras/rdf/rdf.h
monetdb5/extras/rdf/rdfalgebra.c
sql/backends/monet5/sql_rdf.c
Branch: rdf
Log Message:
Implement multi-way merging algorithm for merging BATs of object values for
each property (Slicing from PSO table)
diffs (196 lines):
diff --git a/monetdb5/extras/rdf/rdf.h b/monetdb5/extras/rdf/rdf.h
--- a/monetdb5/extras/rdf/rdf.h
+++ b/monetdb5/extras/rdf/rdf.h
@@ -50,6 +50,9 @@ RDFParser(BAT **graph, str *location, st
rdf_export str
RDFleftfetchjoin_sorted(bat *result, const bat* lid, const bat *rid);
+rdf_export str
+RDFmultiway_merge_outerjoins(int np, BAT **sbats, BAT **obats, BAT **r_sbat,
BAT **r_obats);
+
rdf_export str
TKNZRrdf2str (bat *res, const bat *bid, const bat *map);
diff --git a/monetdb5/extras/rdf/rdfalgebra.c b/monetdb5/extras/rdf/rdfalgebra.c
--- a/monetdb5/extras/rdf/rdfalgebra.c
+++ b/monetdb5/extras/rdf/rdfalgebra.c
@@ -21,8 +21,8 @@
#include "monetdb_config.h"
#include "rdf.h"
+#include "rdfminheap.h"
#include "algebra.h"
-#include <gdk.h>
#include "tokenizer.h"
str
@@ -201,6 +201,118 @@ str RDFtriplesubsort(BAT **sbat, BAT **p
return MAL_SUCCEED;
}
+/* This function RDFmultiway_merge_outerjoins()
+ * is used to create full outer join from multiple
+ * Input:
+ * - np: Number of properties --> == number of obats, number of sbats
+ * - Set of pair of bats corresponding a slice of PSO with certain P value
+ * [bat_s1, bat_o1], [bat_s2, bat_o2],....,[bat_sn, bat_on]
+ * - All bat_si are sorted
+ * Output:
+ * bat_s, bat_o1_new, bat_o2_new, ..., bat_on_new
+ * Where bat_s is union of all bat_s1, ..., bat_sn
+ *
+ * Use a minheap to merge multiple list
+ * */
+str RDFmultiway_merge_outerjoins(int np, BAT **sbats, BAT **obats, BAT
**r_sbat, BAT **r_obats){
+ BUN estimate = 0;
+ int i = 0;
+ MinHeap *hp;
+ MinHeapNode *harr;
+ oid **sbatCursors, **obatCursors;
+ int numMergedS = 0;
+ oid lastS = BUN_NONE;
+ oid tmpO;
+
+ for (i = 0; i < np; i++){
+ estimate += BATcount(obats[i]);
+ }
+
+ sbatCursors = (oid **) malloc(sizeof(oid*) * np);
+ obatCursors = (oid **) malloc(sizeof(oid*) * np);
+
+ *r_sbat = BATnew(TYPE_void, TYPE_oid, estimate, TRANSIENT);
+
+ for (i = 0; i < np; i++){
+ r_obats[i] = BATnew(TYPE_void, TYPE_oid, estimate, TRANSIENT);
+
+ //Keep the cursor to the first element of each input sbats
+ sbatCursors[i] = (oid *) Tloc(sbats[i], BUNfirst(sbats[i]));
+ obatCursors[i] = (oid *) Tloc(obats[i], BUNfirst(obats[i]));
+ }
+
+ //Create a min heap with np heap nodes. Every heap node
+ //has first element of an array (pointing to the first element of each
sbat)
+ harr = (MinHeapNode*)malloc(sizeof(MinHeapNode) * np);
+ for (i = 0; i < np; i++){
+ harr[i].element = sbatCursors[i][0]; //Store the first element
+ harr[i].i = i; //index of array
+ harr[i].j = 1; //Index of next element to be stored from array
+ }
+
+ hp = (MinHeap *) malloc(sizeof(MinHeap));
+ initMinHeap(hp, harr, np); //Create the heap
+
+ //Now one by one get the minimum element from min
+ //heap and replace it with next element of its array
+ numMergedS = 0; //Number of S in the output BAT
+ while (1){
+ //Get the minimum element and store it in output
+ MinHeapNode root = getMin(hp);
+ if (root.element == INT_MAX) break;
+
+ if (lastS != root.element){ //New S
+
+ //Go through all output o_bat to add Null value
+ //if they do not value for the last S
+ for (i = 0; i < np; i++){
+ if (BATcount(r_obats[i]) < (BUN)numMergedS)
+ BUNappend(r_obats[i],
ATOMnilptr(TYPE_oid), TRUE);
+ }
+
+ //Append new s to output sbat
+ BUNappend(*r_sbat, &(root.element), TRUE);
+ //Append the obat corresonding to this root node
+ tmpO = obatCursors[root.i][root.j - 1];
+ BUNappend(r_obats[root.i], &tmpO, TRUE);
+
+ lastS = root.element;
+ (numMergedS)++;
+ }
+ else{
+ //Get element from the corresponding o
+ //Add to the output o
+ tmpO = obatCursors[root.i][root.j - 1];
+ BUNappend(r_obats[root.i], &tmpO, TRUE);
+ }
+
+ //Find the next elelement that will replace current
+ //root of heap. The next element belongs to same
+ //array as the current root.
+ if (root.j < (int) BATcount(sbats[root.i]))
+ {
+ root.element = sbatCursors[root.i][root.j];
+ root.j += 1;
+ }
+ //If root was the last element of its array
+ else root.element = INT_MAX; //INT_MAX is for infinite
+
+ //Replace root with next element of array
+ replaceMin(hp, root);
+ }
+
+ for (i = 0; i < np; i++){
+ if (BATcount(r_obats[i]) < (BUN)numMergedS)
+ BUNappend(r_obats[i], ATOMnilptr(TYPE_oid), TRUE);
+ }
+
+ free(hp);
+ free(harr);
+ free(sbatCursors);
+ free(obatCursors);
+ return MAL_SUCCEED;
+}
+
/*
* Sort left bat and re-order right bat according to the lef bat
* */
diff --git a/sql/backends/monet5/sql_rdf.c b/sql/backends/monet5/sql_rdf.c
--- a/sql/backends/monet5/sql_rdf.c
+++ b/sql/backends/monet5/sql_rdf.c
@@ -1757,10 +1757,10 @@ void getSlides_per_P(PsoPropStat *pso_ps
getOffsets(pso_pstat, p, &l, &h);
- *ret_oBat = BATslice(obat, l, h);
+ *ret_oBat = BATslice(obat, l, h+1);
- *ret_sBat = BATslice(sbat, l, h);
-
+ *ret_sBat = BATslice(sbat, l, h+1);
+ (*ret_sBat)->tsorted = true;
}
@@ -1801,13 +1801,27 @@ void build_PsoPropStat(BAT *full_pbat, i
BATprint(pso_propstat->offsetBat);
{
- BAT *obat, *sbat;
- oid p = 100;
+ BAT **obats, **sbats, *r_sbat, **r_obats;
+ int i;
+ int np = 5;
- getSlides_per_P(pso_propstat, &p, full_obat, full_sbat, &obat,
&sbat);
- printf("Slice of P = "BUNFMT "\n", p);
- BATprint(sbat);
- BATprint(obat);
+ oid props[5] = {100, 200, 400, 500, 700} ;
+ obats = (BAT**)malloc(sizeof(BAT*) * np);
+ sbats = (BAT**)malloc(sizeof(BAT*) * np);
+ r_obats = (BAT**)malloc(sizeof(BAT*) * np);
+
+ for (i = 0; i < np; i++){
+ getSlides_per_P(pso_propstat, &(props[i]),full_obat,
full_sbat, &(obats[i]), &(sbats[i]));
+ }
+
+ RDFmultiway_merge_outerjoins(np, sbats, obats, &r_sbat,
r_obats);
+
+ printf("Outer join result: \n");
+ BATprint(r_sbat);
+ for (i = 0; i < np; i++){
+ BATprint(r_obats[i]);
+ }
+
}
}
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