4 files changed, 24 insertions, 5 deletions
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 8e94d9803f7..bc96ebf68e4 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -230,6 +230,7 @@ typedef enum NodeTag
 	T_SpecialJoinInfo,
 	T_AppendRelInfo,
 	T_PlaceHolderInfo,
+	T_MinMaxAggInfo,
 	T_PlannerParamItem,
 
 	/*
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 6e3d0f35181..f885f5a0c46 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -189,6 +189,8 @@ typedef struct PlannerInfo
 	List	   *distinct_pathkeys;		/* distinctClause pathkeys, if any */
 	List	   *sort_pathkeys;	/* sortClause pathkeys, if any */
 
+	List	   *minmax_aggs;	/* List of MinMaxAggInfos */
+
 	List	   *initial_rels;	/* RelOptInfos we are now trying to join */
 
 	MemoryContext planner_cxt;	/* context holding PlannerInfo */
@@ -1358,6 +1360,23 @@ typedef struct PlaceHolderInfo
 } PlaceHolderInfo;
 
 /*
+ * For each potentially index-optimizable MIN/MAX aggregate function,
+ * root->minmax_aggs stores a MinMaxAggInfo describing it.
+ *
+ * Note: a MIN/MAX agg doesn't really care about the nulls_first property,
+ * so the pathkey's nulls_first flag should be ignored.
+ */
+typedef struct MinMaxAggInfo
+{
+	NodeTag		type;
+
+	Oid			aggfnoid;		/* pg_proc Oid of the aggregate */
+	Oid			aggsortop;		/* Oid of its sort operator */
+	Expr	   *target;			/* expression we are aggregating on */
+	List	   *pathkeys;		/* pathkeys representing needed sort order */
+} MinMaxAggInfo;
+
+/*
  * glob->paramlist keeps track of the PARAM_EXEC slots that we have decided
  * we need for the query.  At runtime these slots are used to pass values
  * around from one plan node to another.  They can be used to pass values
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 6bce53cce57..c0ff0144fa1 100644
--- a/src/include/optimizer/paths.h
+++ b/src/include/optimizer/paths.h
@@ -173,6 +173,9 @@ extern List *make_pathkeys_for_sortclauses(PlannerInfo *root,
 							  List *sortclauses,
 							  List *tlist,
 							  bool canonicalize);
+extern List *make_pathkeys_for_aggregate(PlannerInfo *root,
+										 Expr *aggtarget,
+										 Oid aggsortop);
 extern void initialize_mergeclause_eclasses(PlannerInfo *root,
 											RestrictInfo *restrictinfo);
 extern void update_mergeclause_eclasses(PlannerInfo *root,
@@ -187,10 +190,6 @@ extern List *select_outer_pathkeys_for_merge(PlannerInfo *root,
 extern List *make_inner_pathkeys_for_merge(PlannerInfo *root,
 							  List *mergeclauses,
 							  List *outer_pathkeys);
-extern int pathkeys_useful_for_merging(PlannerInfo *root,
-							RelOptInfo *rel,
-							List *pathkeys);
-extern int	pathkeys_useful_for_ordering(PlannerInfo *root, List *pathkeys);
 extern List *truncate_useless_pathkeys(PlannerInfo *root,
 						  RelOptInfo *rel,
 						  List *pathkeys);
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 5bb0e094e5b..919449b4e38 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -32,6 +32,7 @@ extern void query_planner(PlannerInfo *root, List *tlist,
 /*
  * prototypes for plan/planagg.c
  */
+extern void preprocess_minmax_aggregates(PlannerInfo *root, List *tlist);
 extern Plan *optimize_minmax_aggregates(PlannerInfo *root, List *tlist,
 						   Path *best_path);
 
@@ -39,7 +40,6 @@ extern Plan *optimize_minmax_aggregates(PlannerInfo *root, List *tlist,
  * prototypes for plan/createplan.c
  */
 extern Plan *create_plan(PlannerInfo *root, Path *best_path);
-extern Node *fix_indexqual_operand(Node *node, IndexOptInfo *index);
 extern SubqueryScan *make_subqueryscan(List *qptlist, List *qpqual,
 				  Index scanrelid, Plan *subplan,
 				  List *subrtable, List *subrowmark);