Minor code cleanup: remove no-longer-useful pull_subplans() function,

and convert pull_agg_clause() into count_agg_clause(), which is a more
efficient way of doing what it's really being used for.

Author: tglsfdc

src/backend/optimizer/plan/planner.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.143 2003/02/03 15:07:07 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.144 2003/02/04 00:50:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -623,11 +623,14 @@ grouping_planner(Query *parse, double tuple_fraction)
 		 * Will need actual number of aggregates for estimating costs.
 		 * Also, it's possible that optimization has eliminated all
 		 * aggregates, and we may as well check for that here.
+		 *
+		 * Note: we do not attempt to detect duplicate aggregates here;
+		 * a somewhat-overestimated count is okay for our present purposes.
 		 */
 		if (parse->hasAggs)
 		{
-			numAggs = length(pull_agg_clause((Node *) tlist)) +
-				length(pull_agg_clause(parse->havingQual));
+			numAggs = count_agg_clause((Node *) tlist) +
+				count_agg_clause(parse->havingQual);
 			if (numAggs == 0)
 				parse->hasAggs = false;
 		}

src/backend/optimizer/util/clauses.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.126 2003/02/03 21:15:44 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.127 2003/02/04 00:50:00 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -51,10 +51,9 @@ typedef struct
 
 static bool contain_agg_clause_walker(Node *node, void *context);
 static bool contain_distinct_agg_clause_walker(Node *node, void *context);
-static bool pull_agg_clause_walker(Node *node, List **listptr);
+static bool count_agg_clause_walker(Node *node, int *count);
 static bool expression_returns_set_walker(Node *node, void *context);
 static bool contain_subplans_walker(Node *node, void *context);
-static bool pull_subplans_walker(Node *node, List **listptr);
 static bool contain_mutable_functions_walker(Node *node, void *context);
 static bool contain_volatile_functions_walker(Node *node, void *context);
 static bool contain_nonstrict_functions_walker(Node *node, void *context);
@@ -373,31 +372,28 @@ contain_distinct_agg_clause_walker(Node *node, void *context)
 }
 
 /*
- * pull_agg_clause
- *	  Recursively pulls all Aggref nodes from an expression tree.
- *
- *	  Returns list of Aggref nodes found.  Note the nodes themselves are not
- *	  copied, only referenced.
+ * count_agg_clause
+ *	  Recursively count the Aggref nodes in an expression tree.
  *
  *	  Note: this also checks for nested aggregates, which are an error.
  */
-List *
-pull_agg_clause(Node *clause)
+int
+count_agg_clause(Node *clause)
 {
-	List	   *result = NIL;
+	int			result = 0;
 
-	pull_agg_clause_walker(clause, &result);
+	count_agg_clause_walker(clause, &result);
 	return result;
 }
 
 static bool
-pull_agg_clause_walker(Node *node, List **listptr)
+count_agg_clause_walker(Node *node, int *count)
 {
 	if (node == NULL)
 		return false;
 	if (IsA(node, Aggref))
 	{
-		*listptr = lappend(*listptr, node);
+		(*count)++;
 
 		/*
 		 * Complain if the aggregate's argument contains any aggregates;
@@ -411,8 +407,8 @@ pull_agg_clause_walker(Node *node, List **listptr)
 		 */
 		return false;
 	}
-	return expression_tree_walker(node, pull_agg_clause_walker,
-								  (void *) listptr);
+	return expression_tree_walker(node, count_agg_clause_walker,
+								  (void *) count);
 }
 
 
@@ -511,36 +507,6 @@ contain_subplans_walker(Node *node, void *context)
 	return expression_tree_walker(node, contain_subplans_walker, context);
 }
 
-/*
- * pull_subplans
- *	  Recursively pulls all subplans from an expression tree.
- *
- *	  Returns list of SubPlan nodes found.  Note the nodes themselves
- *	  are not copied, only referenced.
- */
-List *
-pull_subplans(Node *clause)
-{
-	List	   *result = NIL;
-
-	pull_subplans_walker(clause, &result);
-	return result;
-}
-
-static bool
-pull_subplans_walker(Node *node, List **listptr)
-{
-	if (node == NULL)
-		return false;
-	if (is_subplan(node))
-	{
-		*listptr = lappend(*listptr, node);
-		/* fall through to check args to subplan */
-	}
-	return expression_tree_walker(node, pull_subplans_walker,
-								  (void *) listptr);
-}
-
 
 /*****************************************************************************
  *		Check clauses for mutable functions

src/include/optimizer/clauses.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: clauses.h,v 1.61 2003/01/17 03:25:04 tgl Exp $
+ * $Id: clauses.h,v 1.62 2003/02/04 00:50:01 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,12 +46,11 @@ extern List *make_ands_implicit(Expr *clause);
 
 extern bool contain_agg_clause(Node *clause);
 extern bool contain_distinct_agg_clause(Node *clause);
-extern List *pull_agg_clause(Node *clause);
+extern int	count_agg_clause(Node *clause);
 
 extern bool expression_returns_set(Node *clause);
 
 extern bool contain_subplans(Node *clause);
-extern List *pull_subplans(Node *clause);
 
 extern bool contain_mutable_functions(Node *clause);
 extern bool contain_volatile_functions(Node *clause);