Fix for #48: Switched to the filter placement optimizer intended for …

…left joins - although not exactly sure anymore what the code really does

sparqlify-core/src/main/java/org/aksw/sparqlify/database/FilterPlacementOptimizer2.java

@@ -112,7 +112,23 @@ public static Op _optimize(OpTopN op, RestrictionManagerImpl cnf) {
 	}
 
 
+
 	public static Op _optimize(OpJoin op, RestrictionManagerImpl cnf) {
+        Factory2<Op> factory = new Factory2<Op>() {
+            @Override
+            public Op create(Op a, Op b) {
+                Op result = OpJoin.create(a, b);
+                return result;
+            }
+
+        };
+
+        Op result = handleLeftJoin(op.getLeft(), op.getRight(), cnf, factory);
+        return result;      
+
+	}
+
+	public static Op _optimizeBreaking(OpJoin op, RestrictionManagerImpl cnf) {
 
 		RestrictionManagerImpl leftCnf = filterByVars(cnf, op.getLeft());
 		RestrictionManagerImpl rightCnf = filterByVars(cnf, op.getRight());