Remove function isMemoryIntensiveFunction

Historically this function was used to special case a few operators that
were not considered to be MemoryIntensive. However, now it always
returns true. This commit removes the function and also moves the case
for T_FunctionScan in IsMemoryIntensiveOperator into the group that
always returns true, as this is its current behavior

src/backend/utils/resource_manager/memquota.c

@@ -206,24 +206,8 @@ IsBlockingOperator(Node *node)
 	}
 }
 
-/**
- * Special-case certain functions which we know are not memory intensive.
- * TODO caragg 03/04/2014: Revert these changes when ORCA has the new partition
- * operator (MPP-22799)
- *
- */
-static bool
-isMemoryIntensiveFunction(Oid funcid)
-{
-	return true;
-}
-
 /**
  * Is a result node memory intensive? It is if it contains function calls.
- * We special-case certain functions used by ORCA which we know that are not
- * memory intensive
- * TODO caragg 03/04/2014: Revert these changes when ORCA has the new partition
- * operator (MPP-22799)
  */
 bool
 IsResultMemoryIntesive(Result *res)
@@ -233,59 +217,20 @@ IsResultMemoryIntesive(Result *res)
 			(Node *) ((Plan *) res)->targetlist, T_FuncExpr);
 
 	int nFuncExpr = list_length(funcNodes);
+	/* Shallow free of the funcNodes list */
+	list_free(funcNodes);
+	funcNodes = NIL;
 	if (nFuncExpr == 0)
 	{
 		/* No function expressions, not memory intensive */
 		return false;
 	}
-
-	bool isMemoryIntensive = false;
-	ListCell *lc = NULL;
-	foreach(lc, funcNodes)
-	{
-		FuncExpr *funcExpr = lfirst(lc);
-		Assert(IsA(funcExpr, FuncExpr));
-		if ( isMemoryIntensiveFunction(funcExpr->funcid))
-		{
-			/* Found a function that we don't know of. Mark as memory intensive */
-			isMemoryIntensive = true;
-			break;
-		}
-	}
-
-	/* Shallow free of the funcNodes list */
-	list_free(funcNodes);
-	funcNodes = NIL;
-
-	return isMemoryIntensive;
-}
-
-/**
- * Is a function scan memory intensive? Special case some known functions
- * that are not memory intensive.
- */
-static bool
-IsFunctionScanMemoryIntensive(FunctionScan *funcScan, PlannedStmt *stmt)
-{
-	Assert(NULL != stmt);
-	Assert(NULL != funcScan);
-
-	Index rteIndex = funcScan->scan.scanrelid;
-	RangeTblEntry *rte = rt_fetch(rteIndex, stmt->rtable);
-
-	Assert(RTE_FUNCTION == rte->rtekind);
-
-	if (IsA(rte->funcexpr, FuncExpr))
+	else
 	{
-		FuncExpr *funcExpr = (FuncExpr *) rte->funcexpr;
-		return isMemoryIntensiveFunction(funcExpr->funcid);
+		return true;
 	}
-
-	/* Didn't find any of our special cases, default is memory intensive */
-	return true;
 }
 
-
 /**
  * Is an operator memory intensive?
  */
@@ -302,6 +247,7 @@ IsMemoryIntensiveOperator(Node *node, PlannedStmt *stmt)
 		case T_BitmapIndexScan:
 		case T_Window:
 		case T_TableFunctionScan:
+		case T_FunctionScan:
 			return true;
 		case T_Agg:
 			{
@@ -313,11 +259,6 @@ IsMemoryIntensiveOperator(Node *node, PlannedStmt *stmt)
 				Result *res = (Result *) node;
 				return IsResultMemoryIntesive(res);
 			}
-		case T_FunctionScan:
-			{
-				FunctionScan *funcScan = (FunctionScan *) node;
-				return IsFunctionScanMemoryIntensive(funcScan, stmt);
-			}
 		default:
 			return false;
 	}