Changeset: 5750ea4bf154 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=5750ea4bf154
Modified Files:
monetdb5/modules/mal/joinpath.c
monetdb5/modules/mal/joinpath.h
Branch: default
Log Message:
Removal of old joinpath code
The current version only deals with [left]fetchjoin sequences.
Simple oid-chain joins are identified for a possible execution
without intermediates. Looking into larger cases to understand
the actual effectiveness of this is required.
diffs (163 lines):
diff --git a/monetdb5/modules/mal/joinpath.c b/monetdb5/modules/mal/joinpath.c
--- a/monetdb5/modules/mal/joinpath.c
+++ b/monetdb5/modules/mal/joinpath.c
@@ -150,7 +150,87 @@ ALGjoinCost(Client cntxt, BAT *l, BAT *r
return cost;
}
-BAT *
+/*
+ * The joinChain assumes a list of OID columns ending in a projection column.
+ * It is built from leftfetchjoin operations, which allows for easy chaining.
+ * No intermediates are needed and not multistep cost-based evaluation
+ */
+
+#define MAXCHAINDEPTH 256
+
+static BAT *
+ALGjoinChain(Client cntxt, int top, BAT **joins)
+{
+ BAT *bn = NULL;
+ oid lo, hi, *o, oc;
+ BATiter iter[MAXCHAINDEPTH];
+ int i, pcol= top -1;
+ size_t cnt=0, cap=0, empty=0, offset[MAXCHAINDEPTH];
+ const void *v;
+
+#ifdef _DEBUG_JOINPATH_
+ mnstr_printf(cntxt->fdout,"#joinchain \n");
+#else
+ (void) cntxt;
+#endif
+ for ( i =0; i< top ; i++){
+ if( (cnt = BATcount(joins[i]) ) > cap)
+ cap = BATcount(joins[i]);
+ empty += cnt == 0;
+ iter[i] = bat_iterator(joins[i]);
+ offset[i] = BUNfirst(joins[i])-joins[i]->hseqbase;
+ }
+
+ bn = BATnew( TYPE_void, joins[pcol]->ttype, cap, TRANSIENT);
+ if( bn == NULL){
+ GDKerror("joinChain" MAL_MALLOC_FAIL);
+ return NULL;
+ }
+ if ( empty)
+ return bn;
+ /* be optimistic, inherit the properties */
+ bn->T->nonil = joins[pcol]->T->nil;
+ bn->T->nonil = joins[pcol]->T->nonil;
+ bn->tsorted = joins[pcol]->tsorted;
+ bn->trevsorted = joins[pcol]->trevsorted;
+ bn->tkey = joins[pcol]->tkey;
+
+ o = (oid *) BUNtail(iter[0], BUNfirst(joins[0]));
+ for( lo = 0, hi = lo + BATcount(joins[0]); lo < hi && o; o++, lo++)
+ {
+ oc = *o;
+ for(i = 1; i < pcol; i++){
+ v = BUNtail(iter[i], oc + offset[i]);
+ oc = *(oid*) v;
+ if( oc == oid_nil)
+ goto bunins_failed;
+ }
+ // update the join result and keep track of properties
+ v = BUNtail(iter[pcol], oc + offset[pcol]);
+ bunfastapp(bn,v);
+ cnt++;
+ // perform inline property mgmt?
+ // Nonils can not be changed by inclusion of values.
+ // Nils is indicative, not a must that they occur
+ // sorting can be determined by the oids of the last fetch
+ bunins_failed:
+ ;
+ }
+ BATsetcount(bn, cnt);
+ BATseqbase(bn, joins[0]->H->seq);
+
+ // release the chain
+ for ( i =0; i< top ; i++)
+ BBPunfix(joins[i]->batCacheid);
+
+ BATderiveProps(bn, FALSE);
+
+ if (bn && !(bn->batDirty&2)) BATsetaccess(bn, BAT_READ);
+
+ return bn;
+}
+
+static BAT *
ALGjoinPathBody(Client cntxt, int top, BAT **joins, int flag)
{
BAT *b = NULL;
@@ -200,9 +280,6 @@ ALGjoinPathBody(Client cntxt, int top, B
case 1:
b = BATjoin(joins[j], joins[j + 1], (BATcount(joins[j])
< BATcount(joins[j + 1])? BATcount(joins[j]):BATcount(joins[ j + 1])));
break;
- case 2:
- b = BATsemijoin(joins[j], joins[j + 1]);
- break;
case 3:
b = BATproject(joins[j], joins[j + 1]);
break;
@@ -267,13 +344,12 @@ ALGjoinPathBody(Client cntxt, int top, B
str
ALGjoinPath(Client cntxt, MalBlkPtr mb, MalStkPtr stk, InstrPtr pci)
{
- int i,top=0;
+ int i,top=0, chain = 1;
bat *bid;
bat *r = getArgReference_bat(stk, pci, 0);
BAT *b, **joins = (BAT**)GDKmalloc(pci->argc*sizeof(BAT*));
int error = 0;
str joinPathRef = putName("joinPath",8);
- str semijoinPathRef = putName("semijoinPath",12);
str leftjoinPathRef = putName("leftjoinPath",12);
if ( joins == NULL)
@@ -298,10 +374,16 @@ ALGjoinPath(Client cntxt, MalBlkPtr mb,
}
joins[top++] = b;
}
+ /* detect easy chain joins */
+ for ( i =1; i< top ; i++)
+ if( BATcount(joins[i-1])> BATcount(joins[i]) )
+ chain = 0;
+ chain = 0; // disabled for the moment, because it is not robust yet
+
ALGODEBUG{
char *ps;
ps = instruction2str(mb, 0, pci, 0);
- fprintf(stderr,"#joinpath %s\n", ps ? ps : "");
+ fprintf(stderr,"#joinpath [%s] %s\n", (ps ? ps : ""),
chain?"chain":"diverse");
GDKfree(ps);
}
if ( getFunctionId(pci) == joinPathRef)
@@ -309,11 +391,12 @@ ALGjoinPath(Client cntxt, MalBlkPtr mb,
else
if ( getFunctionId(pci) == leftjoinPathRef)
b= ALGjoinPathBody(cntxt,top,joins, 0);
- else
- if ( getFunctionId(pci) == semijoinPathRef)
- b= ALGjoinPathBody(cntxt,top,joins, 2);
- else
- b= ALGjoinPathBody(cntxt,top,joins, 3);
+ else{
+ if( chain && top < MAXCHAINDEPTH)
+ b= ALGjoinChain(cntxt,top,joins);
+ else
+ b= ALGjoinPathBody(cntxt,top,joins, 3);
+ }
GDKfree(joins);
if ( b)
diff --git a/monetdb5/modules/mal/joinpath.h b/monetdb5/modules/mal/joinpath.h
--- a/monetdb5/modules/mal/joinpath.h
+++ b/monetdb5/modules/mal/joinpath.h
@@ -23,6 +23,5 @@
#endif
join_export str ALGjoinPath(Client cntxt, MalBlkPtr mb, MalStkPtr stk,
InstrPtr pci);
-join_export BAT * ALGjoinPathBody(Client cntxt, int top, BAT **joins, int
flag);
#endif
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