Пример #1
0
int
OPTevaluateImplementation(Client cntxt, MalBlkPtr mb, MalStkPtr stk, InstrPtr pci)
{
	InstrPtr p;
	int i, k, limit, *alias, barrier;
	MalStkPtr env = NULL;
	int profiler;
	str msg;
	int debugstate = cntxt->itrace, actions = 0, constantblock = 0;
	int *assigned, setonce; 

	cntxt->itrace = 0;
	(void)stk;
	(void)pci;

	if (varGetProp(mb, getArg(mb->stmt[0], 0), inlineProp) != NULL)
		return 0;

	(void)cntxt;
	OPTDEBUGevaluate mnstr_printf(cntxt->fdout, "Constant expression optimizer started\n");

	assigned = (int*) GDKzalloc(sizeof(int) * mb->vtop);
	if (assigned == NULL)
		return 0;

	alias = (int*)GDKzalloc(mb->vsize * sizeof(int) * 2); /* we introduce more */
	if (alias == NULL){
		GDKfree(assigned);
		return 0;
	}

	// arguments are implicitly assigned by context
	p = getInstrPtr(mb, 0);
	for ( k =p->retc;  k < p->argc; k++)
		assigned[getArg(p,k)]++;
	limit = mb->stop;
	for (i = 1; i < limit; i++) {
		p = getInstrPtr(mb, i);
		// The double count emerging from a barrier exit is ignored.
		if (! blockExit(p) || (blockExit(p) && p->retc != p->argc))
		for ( k =0;  k < p->retc; k++)
			assigned[getArg(p,k)]++;
	}

	for (i = 1; i < limit; i++) {
		p = getInstrPtr(mb, i);
		for (k = p->retc; k < p->argc; k++)
			if (alias[getArg(p, k)])
				getArg(p, k) = alias[getArg(p, k)];
		// to avoid management of duplicate assignments over multiple blocks
		// we limit ourselfs to evaluation of the first assignment only.
		setonce = assigned[getArg(p,0)] == 1;
		OPTDEBUGevaluate printInstruction(cntxt->fdout, mb, 0, p, LIST_MAL_ALL);
		constantblock +=  blockStart(p) && OPTallConstant(cntxt,mb,p);

		/* be aware that you only assign once to a variable */
		if (setonce && p->retc == 1 && OPTallConstant(cntxt, mb, p) && !isUnsafeFunction(p)) {
			barrier = p->barrier;
			p->barrier = 0;
			profiler = malProfileMode;	/* we don't trace it */
			malProfileMode = 0;
			if ( env == NULL) {
				env = prepareMALstack(mb,  2 * mb->vsize );
				env->keepAlive = TRUE;
			}
			msg = reenterMAL(cntxt, mb, i, i + 1, env);
			malProfileMode= profiler;
			p->barrier = barrier;
			OPTDEBUGevaluate {
				mnstr_printf(cntxt->fdout, "#retc var %s\n", getVarName(mb, getArg(p, 0)));
				mnstr_printf(cntxt->fdout, "#result:%s\n", msg == MAL_SUCCEED ? "ok" : msg);
			}
			if (msg == MAL_SUCCEED) {
				int nvar;
				ValRecord cst;

				actions++;
				cst.vtype = 0;
				VALcopy(&cst, &env->stk[getArg(p, 0)]);
				/* You may not overwrite constants.  They may be used by
				 * other instructions */
				nvar = getArg(p, 1) = defConstant(mb, getArgType(mb, p, 0), &cst);
				if (nvar >= env->stktop) {
					VALcopy(&env->stk[getArg(p, 1)], &getVarConstant(mb, getArg(p, 1)));
					env->stktop = getArg(p, 1) + 1;
				}
				alias[getArg(p, 0)] = getArg(p, 1);
				p->argc = 2;
				p->token = ASSIGNsymbol;
				clrFunction(p);
				p->barrier = barrier;
				/* freeze the type */
				setVarFixed(mb,getArg(p,1));
				setVarUDFtype(mb,getArg(p,1));
				OPTDEBUGevaluate {
					mnstr_printf(cntxt->fdout, "Evaluated new constant=%d -> %d:%s\n",
						getArg(p, 0), getArg(p, 1), getTypeName(getArgType(mb, p, 1)));
				}
			} else {
Пример #2
0
int
OPTpushselectImplementation(Client cntxt, MalBlkPtr mb, MalStkPtr stk, InstrPtr pci)
{
	int i, j, limit, slimit, actions=0, *vars, push_down_delta = 0, nr_topn = 0, nr_likes = 0;
	InstrPtr p, *old;
	subselect_t subselects;

	memset(&subselects, 0, sizeof(subselects));
	if( mb->errors) 
		return 0;

	OPTDEBUGpushselect
		mnstr_printf(cntxt->fdout,"#Push select optimizer started\n");
	(void) stk;
	(void) pci;
	vars= (int*) GDKzalloc(sizeof(int)* mb->vtop);
	if( vars == NULL)
		return 0;

	limit = mb->stop;
	slimit= mb->ssize;
	old = mb->stmt;

	/* check for bailout conditions */
	for (i = 1; i < limit; i++) {
		int lastbat;
		p = old[i];

		for (j = 0; j<p->retc; j++) {
 			int res = getArg(p, j);
			vars[res] = i;
		}

		if (getModuleId(p) == algebraRef && 
			(getFunctionId(p) == tintersectRef || getFunctionId(p) == tinterRef || 
			 getFunctionId(p) == tdifferenceRef || getFunctionId(p) == tdiffRef)) {
			GDKfree(vars);
			return 0;
		}

		if (getModuleId(p) == algebraRef && getFunctionId(p) == sliceRef)
			nr_topn++;

		if (isLikeOp(p))
			nr_likes++;

		if (getModuleId(p) == sqlRef && getFunctionId(p) == deltaRef)
			push_down_delta++;

		if (getModuleId(p) == sqlRef && getFunctionId(p) == tidRef) { /* rewrite equal table ids */
			int sname = getArg(p, 2), tname = getArg(p, 3), s;

			for (s = 0; s < subselects.nr; s++) {
				InstrPtr q = old[vars[subselects.tid[s]]];
				int Qsname = getArg(q, 2), Qtname = getArg(q, 3);

				if (no_updates(old, vars, getArg(q,1), getArg(p,1)) &&
				    ((sname == Qsname && tname == Qtname) ||
				    (0 && strcmp(getVarConstant(mb, sname).val.sval, getVarConstant(mb, Qsname).val.sval) == 0 &&
				     strcmp(getVarConstant(mb, tname).val.sval, getVarConstant(mb, Qtname).val.sval) == 0))) {
					clrFunction(p);
					p->retc = 1;
					p->argc = 2;
					getArg(p, 1) = getArg(q, 0);
					break;
				}
			}
		}
		lastbat = lastbat_arg(mb, p);
		if (isSubSelect(p) && p->retc == 1 &&
		   /* no cand list */ getArgType(mb, p, lastbat) != newBatType(TYPE_oid, TYPE_oid)) {
			int i1 = getArg(p, 1), tid = 0;
			InstrPtr q = old[vars[i1]];

			/* find the table ids */
			while(!tid) {
				if (getModuleId(q) == algebraRef && getFunctionId(q) == leftfetchjoinRef) {
					int i1 = getArg(q, 1);
					InstrPtr s = old[vars[i1]];
	
					if (getModuleId(s) == sqlRef && getFunctionId(s) == tidRef) 
						tid = getArg(q, 1);
					if (s->argc == 2 && s->retc == 1) {
						int i1 = getArg(s, 1);
						InstrPtr s = old[vars[i1]];
						if (getModuleId(s) == sqlRef && getFunctionId(s) == tidRef) 
							tid = getArg(q, 1);
					}
					break;
				} else if (isMapOp(q) && q->argc >= 2 && isaBatType(getArgType(mb, q, 1))) {
					int i1 = getArg(q, 1);
					q = old[vars[i1]];
				} else if (isMapOp(q) && q->argc >= 3 && isaBatType(getArgType(mb, q, 2))) {
					int i2 = getArg(q, 2);
					q = old[vars[i2]];
				} else {
					break;
				}
			}
			if (tid && subselect_add(&subselects, tid, getArg(p, 0)) < 0) {
				GDKfree(vars);
				return 0;
			}
		}
		/* left hand side */
		if ( (GDKdebug & (1<<15)) &&
		     isMatJoinOp(p) && p->retc == 2) { 
			int i1 = getArg(p, 2), tid = 0;
			InstrPtr q = old[vars[i1]];

			/* find the table ids */
			while(!tid) {
				if (getModuleId(q) == algebraRef && getFunctionId(q) == leftfetchjoinRef) {
					int i1 = getArg(q, 1);
					InstrPtr s = old[vars[i1]];
	
					if (getModuleId(s) == sqlRef && getFunctionId(s) == tidRef) 
						tid = getArg(q, 1);
					break;
				} else if (isMapOp(q) && q->argc >= 2 && isaBatType(getArgType(mb, q, 1))) {
					int i1 = getArg(q, 1);
					q = old[vars[i1]];
				} else if (isMapOp(q) && q->argc >= 3 && isaBatType(getArgType(mb, q, 2))) {
					int i2 = getArg(q, 2);
					q = old[vars[i2]];
				} else {
					break;
				}
			}
			if (tid && subselect_add(&subselects, tid, getArg(p, 0)) < 0) {
				GDKfree(vars);
				return 0;
			}
		}
		/* right hand side */
		if ( (GDKdebug & (1<<15)) &&
		     isMatJoinOp(p) && p->retc == 2) { 
			int i1 = getArg(p, 3), tid = 0;
			InstrPtr q = old[vars[i1]];

			/* find the table ids */
			while(!tid) {
				if (getModuleId(q) == algebraRef && getFunctionId(q) == leftfetchjoinRef) {
					int i1 = getArg(q, 1);
					InstrPtr s = old[vars[i1]];
	
					if (getModuleId(s) == sqlRef && getFunctionId(s) == tidRef) 
						tid = getArg(q, 1);
					break;
				} else if (isMapOp(q) && q->argc >= 2 && isaBatType(getArgType(mb, q, 1))) {
					int i1 = getArg(q, 1);
					q = old[vars[i1]];
				} else if (isMapOp(q) && q->argc >= 3 && isaBatType(getArgType(mb, q, 2))) {
					int i2 = getArg(q, 2);
					q = old[vars[i2]];
				} else {
					break;
				}
			}
			if (tid && subselect_add(&subselects, tid, getArg(p, 1)) < 0) {
				GDKfree(vars);
				return 0;
			}
		}
	}

	if ((!subselects.nr && !nr_topn && !nr_likes) || newMalBlkStmt(mb, mb->ssize) <0 ) {
		GDKfree(vars);
		return 0;
	}
	pushInstruction(mb,old[0]);

	for (i = 1; i < limit; i++) {
		p = old[i];

		/* rewrite batalgebra.like + subselect -> likesubselect */
		if (getModuleId(p) == algebraRef && p->retc == 1 && getFunctionId(p) == subselectRef) { 
			int var = getArg(p, 1);
			InstrPtr q = mb->stmt[vars[var]]; /* BEWARE: the optimizer may not add or remove statements ! */

			if (isLikeOp(q)) { /* TODO check if getArg(p, 3) value == TRUE */
				InstrPtr r = newInstruction(mb, ASSIGNsymbol);
				int has_cand = (getArgType(mb, p, 2) == newBatType(TYPE_oid, TYPE_oid)); 
				int a, anti = (getFunctionId(q)[0] == 'n'), ignore_case = (getFunctionId(q)[anti?4:0] == 'i');

				setModuleId(r, algebraRef);
				setFunctionId(r, likesubselectRef);
				getArg(r,0) = getArg(p,0);
				r = pushArgument(mb, r, getArg(q, 1));
				if (has_cand)
					r = pushArgument(mb, r, getArg(p, 2));
				for(a = 2; a<q->argc; a++)
					r = pushArgument(mb, r, getArg(q, a));
				if (r->argc < (4+has_cand))
					r = pushStr(mb, r, ""); /* default esc */ 
				if (r->argc < (5+has_cand))
					r = pushBit(mb, r, ignore_case);
				if (r->argc < (6+has_cand))
					r = pushBit(mb, r, anti);
				freeInstruction(p);
				p = r;
				actions++;
			}
		}

		/* inject table ids into subselect 
		 * s = subselect(c, C1..) => subselect(c, t, C1..)
		 */
		if (isSubSelect(p) && p->retc == 1) { 
			int tid = 0;

			if ((tid = subselect_find_tids(&subselects, getArg(p, 0))) >= 0) {
				int lastbat = lastbat_arg(mb, p);
				if (getArgType(mb, p, lastbat) == TYPE_bat) /* empty candidate list bat_nil */
					getArg(p, lastbat) = tid;
				else
					p = PushArgument(mb, p, tid, lastbat+1);
				/* make sure to resolve again */
				p->token = ASSIGNsymbol; 
				p->typechk = TYPE_UNKNOWN;
        			p->fcn = NULL;
        			p->blk = NULL;
				actions++;
			}
		}
		else if ( (GDKdebug & (1<<15)) &&
			 isMatJoinOp(p) && p->retc == 2
			 && !(getFunctionId(p) == joinRef && p->argc > 4)
			 ) { 
			int ltid = 0, rtid = 0, done = 0;
			int range = 0;

			if(getFunctionId(p) == joinRef)
				range = (p->argc >= 4);

			if ((ltid = subselect_find_tids(&subselects, getArg(p, 0))) >= 0 && 
			    (rtid = subselect_find_tids(&subselects, getArg(p, 1))) >= 0) {
				p = PushArgument(mb, p, ltid, 4+range);
				p = PushArgument(mb, p, rtid, 5+range);
				done = 1;
			} else if ((ltid = subselect_find_tids(&subselects, getArg(p, 0))) >= 0) { 
				p = PushArgument(mb, p, ltid, 4+range);
				p = PushNil(mb, p, 5+range, TYPE_bat); 
				done = 1;
			} else if ((rtid = subselect_find_tids(&subselects, getArg(p, 1))) >= 0) {
				p = PushNil(mb, p, 4+range, TYPE_bat); 
				p = PushArgument(mb, p, rtid, 5+range);
				done = 1;
			}
			if (done) {
				if(getFunctionId(p) == antijoinRef)
					p = pushInt(mb, p, JOIN_NE); 
				p = pushBit(mb, p, FALSE); /* do not match nils */
				p = pushNil(mb, p, TYPE_lng); /* no estimate */

				/* TODO join* -> subjoin* */
				if(getFunctionId(p) == joinRef)
					getFunctionId(p) = subjoinRef;
				else if(getFunctionId(p) == antijoinRef)
					getFunctionId(p) = subthetajoinRef;
				else if(getFunctionId(p) == thetajoinRef)
					getFunctionId(p) = subthetajoinRef;
				else if(getFunctionId(p) == bandjoinRef)
					getFunctionId(p) = subbandjoinRef;
				/* make sure to resolve again */
				p->token = ASSIGNsymbol; 
				p->typechk = TYPE_UNKNOWN;
        			p->fcn = NULL;
        			p->blk = NULL;
				actions++;
			}
		}
		/* Leftfetchjoins involving rewriten table ids need to be flattend
		 * l = leftfetchjoin(t, c); => l = c;
		 * and
		 * l = leftfetchjoin(s, ntids); => l = s;
		 */
		else if (getModuleId(p) == algebraRef && getFunctionId(p) == leftfetchjoinRef) {
			int var = getArg(p, 1);
			
			if (subselect_find_subselect(&subselects, var) > 0) {
				InstrPtr q = newAssignment(mb);

				getArg(q, 0) = getArg(p, 0); 
				(void) pushArgument(mb, q, getArg(p, 2));
				actions++;
				freeInstruction(p);
				continue;
			} else { /* deletes/updates use table ids */
				int var = getArg(p, 2);
				InstrPtr q = mb->stmt[vars[var]]; /* BEWARE: the optimizer may not add or remove statements ! */

				if (q->token == ASSIGNsymbol) {
					var = getArg(q, 1);
					q = mb->stmt[vars[var]]; 
				}
				if (subselect_find_subselect(&subselects, var) > 0) {
					InstrPtr qq = newAssignment(mb);
					/* TODO: check result */

					getArg(qq, 0) = getArg(p, 0); 
					(void) pushArgument(mb, qq, getArg(p, 1));
					actions++;
					freeInstruction(p);
					continue;
				}
				/* c = sql.delta(b,uid,uval,ins);
		 		 * l = leftfetchjoin(x, c); 
		 		 * into
		 		 * l = sql.projectdelta(x,b,uid,uval,ins);
		 		 */
				else if (getModuleId(q) == sqlRef && getFunctionId(q) == deltaRef && q->argc == 5) {
					q = copyInstruction(q);
					setFunctionId(q, projectdeltaRef);
					getArg(q, 0) = getArg(p, 0); 
					q = PushArgument(mb, q, getArg(p, 1), 1);
					freeInstruction(p);
					p = q;
					actions++;
				}
			}
		}
		pushInstruction(mb,p);
	}
	for (; i<limit; i++) 
		if (old[i])
			pushInstruction(mb,old[i]);
	for (; i<slimit; i++) 
		if (old[i])
			freeInstruction(old[i]);
	GDKfree(old);
	if (!push_down_delta) {
		GDKfree(vars);
		return actions;
	}

	/* now push selects through delta's */
	limit = mb->stop;
	slimit= mb->ssize;
	old = mb->stmt;

	if (newMalBlkStmt(mb, mb->stop+(5*push_down_delta)) <0 ) {
		mb->stmt = old;
		GDKfree(vars);
		return actions;

	}
	pushInstruction(mb,old[0]);

	for (i = 1; i < limit; i++) {
		int lastbat;
		p = old[i];

		for (j = 0; j<p->retc; j++) {
 			int res = getArg(p, j);
			vars[res] = i;
		}

		/* push subslice under projectdelta */
		if (isSlice(p) && p->retc == 1) {
			int var = getArg(p, 1);
			InstrPtr q = old[vars[var]];
			if (getModuleId(q) == sqlRef && getFunctionId(q) == projectdeltaRef) {
				InstrPtr r = copyInstruction(p);
				InstrPtr s = copyInstruction(q);
				ValRecord cst;

				/* slice the candidates */
				setFunctionId(r, sliceRef);
				getArg(r, 0) = newTmpVariable(mb, newBatType(TYPE_oid, TYPE_oid));
				getArg(r, 1) = getArg(s, 1); 
				cst.vtype = getArgType(mb, r, 2);
				cst.val.wval = 0;
				getArg(r, 2) = defConstant(mb, cst.vtype, &cst); /* start from zero */
				pushInstruction(mb,r);

				/* dummy result for the old q, will be removed by deadcode optimizer */
				getArg(q, 0) = newTmpVariable(mb, getArgType(mb, q, 0));

				getArg(s, 1) = getArg(r, 0); /* use result of subslice */
				pushInstruction(mb, s);
			}
		}
		/* c = delta(b, uid, uvl, ins)
		 * s = subselect(c, C1..)
		 *
		 * nc = subselect(b, C1..)
		 * ni = subselect(ins, C1..)
		 * nu = subselect(uvl, C1..)
		 * s = subdelta(nc, uid, nu, ni);
		 *
		 * doesn't handle Xsubselect(x, .. z, C1.. cases) ie multicolumn selects
		 */
		lastbat = lastbat_arg(mb, p);
		if (isSubSelect(p) && p->retc == 1 && lastbat == 2) {
			int var = getArg(p, 1);
			InstrPtr q = old[vars[var]];

			if (q->token == ASSIGNsymbol) {
				var = getArg(q, 1);
				q = old[vars[var]]; 
			}
			if (getModuleId(q) == sqlRef && getFunctionId(q) == deltaRef) {
				InstrPtr r = copyInstruction(p);
				InstrPtr s = copyInstruction(p);
				InstrPtr t = copyInstruction(p);
				InstrPtr u = copyInstruction(q);
		
				getArg(r, 0) = newTmpVariable(mb, newBatType(TYPE_oid, TYPE_oid));
				getArg(r, 1) = getArg(q, 1); /* column */
				pushInstruction(mb,r);
				getArg(s, 0) = newTmpVariable(mb, newBatType(TYPE_oid, TYPE_oid));
				getArg(s, 1) = getArg(q, 3); /* updates */
				s = ReplaceWithNil(mb, s, 2, TYPE_bat); /* no candidate list */
				setArgType(mb, s, 2, newBatType(TYPE_oid,TYPE_oid));
				/* make sure to resolve again */
				s->token = ASSIGNsymbol; 
				s->typechk = TYPE_UNKNOWN;
        			s->fcn = NULL;
        			s->blk = NULL;
				pushInstruction(mb,s);
				getArg(t, 0) = newTmpVariable(mb, newBatType(TYPE_oid, TYPE_oid));
				getArg(t, 1) = getArg(q, 4); /* inserts */
				pushInstruction(mb,t);

				setFunctionId(u, subdeltaRef);
				getArg(u, 0) = getArg(p,0);
				getArg(u, 1) = getArg(r,0);
				getArg(u, 2) = getArg(p,2); /* pre-cands */
				getArg(u, 3) = getArg(q,2); /* update ids */
				getArg(u, 4) = getArg(s,0);
				u = pushArgument(mb, u, getArg(t,0));
				pushInstruction(mb,u);	
				freeInstruction(p);
				continue;
			}
		}
		pushInstruction(mb,p);
	}
	for (; i<limit; i++) 
		if (old[i])
			pushInstruction(mb,old[i]);
	GDKfree(vars);
	GDKfree(old);
	return actions;
}
Пример #3
0
str
OPTevaluateImplementation(Client cntxt, MalBlkPtr mb, MalStkPtr stk, InstrPtr pci)
{
	InstrPtr p;
	int i, k, limit, *alias = 0, barrier;
	MalStkPtr env = NULL;
	int profiler;
	int debugstate = cntxt->itrace, actions = 0, constantblock = 0;
	int *assigned = 0, use; 
	char buf[256];
	lng usec = GDKusec();
	str msg = MAL_SUCCEED;

	(void)stk;
	(void)pci;

	if ( mb->inlineProp )
		return MAL_SUCCEED;

	cntxt->itrace = 0;

#ifdef DEBUG_OPT_EVALUATE
	fprintf(stderr, "Constant expression optimizer started\n");
#endif

	assigned = (int*) GDKzalloc(sizeof(int) * mb->vtop);
	if (assigned == NULL)
		throw(MAL,"optimzier.evaluate", SQLSTATE(HY001) MAL_MALLOC_FAIL);

	alias = (int*)GDKzalloc(mb->vsize * sizeof(int) * 2); /* we introduce more */
	if (alias == NULL){
		GDKfree(assigned);
		throw(MAL,"optimzier.evaluate", SQLSTATE(HY001) MAL_MALLOC_FAIL);
	}

	// arguments are implicitly assigned by context
	p = getInstrPtr(mb, 0);
	for ( k =p->retc;  k < p->argc; k++)
		assigned[getArg(p,k)]++;
	limit = mb->stop;
	for (i = 1; i < limit; i++) {
		p = getInstrPtr(mb, i);
		// The double count emerging from a barrier exit is ignored.
		if (! blockExit(p) || (blockExit(p) && p->retc != p->argc))
		for ( k =0;  k < p->retc; k++)
		if ( p->retc != p->argc || p->token != ASSIGNsymbol )
			assigned[getArg(p,k)]++;
	}

	for (i = 1; i < limit && cntxt->mode != FINISHCLIENT; i++) {
		p = getInstrPtr(mb, i);
		// to avoid management of duplicate assignments over multiple blocks
		// we limit ourselves to evaluation of the first assignment only.
		use = assigned[getArg(p,0)] == 1 && !(p->argc == p->retc && blockExit(p));
		for (k = p->retc; k < p->argc; k++)
			if (alias[getArg(p, k)])
				getArg(p, k) = alias[getArg(p, k)];
#ifdef DEBUG_OPT_EVALUATE
		fprintInstruction(stderr , mb, 0, p, LIST_MAL_ALL);
#endif
		/* be aware that you only assign once to a variable */
		if (use && p->retc == 1 && OPTallConstant(cntxt, mb, p) && !isUnsafeFunction(p)) {
			barrier = p->barrier;
			p->barrier = 0;
			profiler = malProfileMode;	/* we don't trace it */
			malProfileMode = 0;
			if ( env == NULL) {
				env = prepareMALstack(mb,  2 * mb->vsize);
				if (!env) {
					msg = createException(MAL,"optimizer.evaluate", SQLSTATE(HY001) MAL_MALLOC_FAIL);
					goto wrapup;
				}
				env->keepAlive = TRUE;
			}
			msg = reenterMAL(cntxt, mb, i, i + 1, env);
			malProfileMode= profiler;
			p->barrier = barrier;
#ifdef DEBUG_OPT_EVALUATE
			fprintf(stderr, "#retc var %s\n", getVarName(mb, getArg(p, 0)));
			fprintf(stderr, "#result:%s\n", msg == MAL_SUCCEED ? "ok" : msg);
#endif
			if (msg == MAL_SUCCEED) {
				int nvar;
				ValRecord cst;

				actions++;
				cst.vtype = 0;
				VALcopy(&cst, &env->stk[getArg(p, 0)]);
				/* You may not overwrite constants.  They may be used by
				 * other instructions */
				nvar = getArg(p, 1) = defConstant(mb, getArgType(mb, p, 0), &cst);
				if (nvar >= env->stktop) {
					VALcopy(&env->stk[getArg(p, 1)], &getVarConstant(mb, getArg(p, 1)));
					env->stktop = getArg(p, 1) + 1;
				}
				alias[getArg(p, 0)] = getArg(p, 1);
				p->argc = 2;
				p->token = ASSIGNsymbol;
				clrFunction(p);
				p->barrier = barrier;
				/* freeze the type */
				setVarFixed(mb,getArg(p,1));
				setVarUDFtype(mb,getArg(p,1));
#ifdef DEBUG_OPT_EVALUATE
				{str tpename;
				fprintf(stderr, "Evaluated new constant=%d -> %d:%s\n",
					getArg(p, 0), getArg(p, 1), tpename = getTypeName(getArgType(mb, p, 1)));
				GDKfree(tpename);
				}
#endif
			} else {
				/* if there is an error, we should postpone message handling,
					as the actual error (eg. division by zero ) may not happen) */
#ifdef DEBUG_OPT_EVALUATE
				fprintf(stderr, "Evaluated %s\n", msg);
#endif
				freeException(msg);
				msg= MAL_SUCCEED;
				mb->errors = 0;
			}
		}
		constantblock +=  blockStart(p) && OPTallConstant(cntxt, mb, p);	/* default */
	}
	// produces errors in SQL when enabled
	if ( constantblock)
		msg = OPTremoveUnusedBlocks(cntxt, mb);
	cntxt->itrace = debugstate;

    /* Defense line against incorrect plans */
	/* Plan is unaffected */
	chkTypes(cntxt->usermodule, mb, FALSE);
	chkFlow(mb);
	chkDeclarations(mb);
    
    /* keep all actions taken as a post block comment */
	usec = GDKusec()- usec;
    snprintf(buf,256,"%-20s actions=%2d time=" LLFMT " usec","evaluate",actions,usec);
    newComment(mb,buf);
	if( actions >= 0)
		addtoMalBlkHistory(mb);

wrapup:
	if ( env) freeStack(env);
	if(assigned) GDKfree(assigned);
	if(alias)	GDKfree(alias);
	return msg;
}