Changeset: a92ae9caed14 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=a92ae9caed14
Modified Files:
monetdb5/extras/crackers/opt_selcrack.mx
Branch: holindex
Log Message:
Crackers: minor optimizer change:
replace
x1 := uselect(x0,...);
x2 := leftjoin(x1,x0);
by
x2 := select(x0,...);
in case of
select a from t where a between X and Y;
diffs (138 lines):
diff --git a/monetdb5/extras/crackers/opt_selcrack.mx
b/monetdb5/extras/crackers/opt_selcrack.mx
--- a/monetdb5/extras/crackers/opt_selcrack.mx
+++ b/monetdb5/extras/crackers/opt_selcrack.mx
@@ -59,7 +59,7 @@ OPTselcrackImplementation(Client cntxt,
{
InstrPtr p, *old;
int update= 0, i, limit, actions=0, j;
-
+ int no_of_leftjoins=0;
str tables[maxTables];
int crackedTables=0;
@@ -69,10 +69,22 @@ OPTselcrackImplementation(Client cntxt,
OPTDEBUGselcrack
printf("Crack optimizer started\n");
- (void) cntxt;
- (void) stk;
+
+ (void) cntxt;/* Tell compilers that we know that we do not */
+ (void) stk; /* use these function parameters, here. */
(void) pci;
+ /* In general, a MAL optimizer transforms a given MAL program into a
+ * modified one by sequentially walking through the given program
+ * and concurrently creating a new one from scratch by
+ * (1) copying statements as is, modified, or in a different order,
+ * or (2) omitting statements or (3) introducing new statements.
+ */
+
+ /* check for logical error: mb must never be NULL */
+ assert (mb != NULL);
+
+ /* safe the old stage of the MAL block */
limit = mb->stop;
old = mb->stmt;
@@ -85,7 +97,15 @@ OPTselcrackImplementation(Client cntxt,
}
if (update)
return 0;
+ /*If there are more than one leftjoins in the plan, we do not want to
replace or delete none of them*/
+ for (i = 0; i < limit; i++) {
+ p = old[i];
+ if (match2(old[j], algebraRef, leftjoinRef))
+ no_of_leftjoins++;
+ }
+
+ /* iterate over the instructions of the input MAL program */
for (i = 0; i < limit; i++) {
p = old[i];
@@ -110,10 +130,12 @@ OPTselcrackImplementation(Client cntxt,
if (mb->var[getArg(p,5)]->value.val.ival != 0 )
continue;
- varSetProp(mb, getArg(p, 0), canBeCrackedProp, 0, NULL);
+ varSetProp(mb, getArg(p, 0), canBeCrackedProp, 0,
NULL); /* add a property "can be cracked" to every base relation that is a
candidate for selection cracking */
- vp = VALset(&v, TYPE_str,
GDKstrdup(getVar(mb,getArg(p,2))->value.val.sval));
+
+ vp = VALset(&v, TYPE_str,
GDKstrdup(getVar(mb,getArg(p,2))->value.val.sval)); /* also, for every
candidate bat, maintain the table name */
varSetProp(mb, getArg(p,0), tableProp, op_eq, vp);
+
continue;
}
@@ -147,6 +169,11 @@ OPTselcrackImplementation(Client cntxt,
if (match2(p, algebraRef, selectRef) ||
match2(p, algebraRef, uselectRef) ||
match2(p, algebraRef, thetauselectRef)){
+
+
+ int j=0,k=0,m=0;
+ bit found = FALSE;
+ bit found2 = FALSE;
if (varGetProp(mb, getArg(p,1), canBeCrackedProp) !=
NULL){
bit alreadyCracked = FALSE;
@@ -160,10 +187,56 @@ OPTselcrackImplementation(Client cntxt,
if (!alreadyCracked){
tables[crackedTables]=GDKstrdup(varGetProp(mb, getArg(p,1),
tableProp)->value.val.sval);
crackedTables++;
- setModuleId(p,putName("crackers",8));
+ if (match2(p, algebraRef, uselectRef))
+ {
+ setFunctionId(p,
putName("select", 6));
+
+ }
+ else if (match2(p, algebraRef,
thetauselectRef))
+ {
+ setFunctionId(p,
putName("thetaselect", 11));
+
+ }
+
+ setModuleId(p, putName("crackers", 8));
+
+ setVarType(mb, getArg(p,0),
getArgType(mb,p,1)); /*We force the return type to be equal to the type of the
first argument*/
+ setVarUDFtype(mb, getArg(p,0));
+
+ for (j = i+1; !found && j <
limit; j++){
+ if(match2(old[j], algebraRef,
semijoinRef) || no_of_leftjoins>1)
+ { break; }
+ if (match2(old[j], algebraRef,
leftjoinRef)){
+ for (k = old[j]->retc;
!found && k < old[j]->argc; k++)
+ found =
(getArg(old[j], k) == getArg(p, 1));
+ if(found)
+ {
+ for (m = j+1; m
< limit; m++)
+ {
+ for (k
= old[m]->retc; k < old[m]->argc; k++){
+
found2 = (getArg(old[m], k) == getArg(old[j], 0));
+
if (found2)
+
break;
+
+ }
+
getArg(old[m], k) = getArg(p, 0);
+
+
+
continue;
+
+ }
+
+ }
+ }
+
+ continue;
+ }
+
+
actions++;
continue;
}
+
}
}
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